So, how can a nihilist find something to live for, if they believe that the world is meaningless? I propose self-fulfillment, which is perhaps a toned-down or realistic/sustainable version of hedonism, in a way.

For indeed, if there is no singular goal or purpose in life, then what's the point of striving and putting yourself through needless trials and tribulations? One needn't find a reason to live, if one is content with life. For if life fulfills you, then there is no reason or appeal to death. Thus, perhaps we may find that kind of satisfaction and contentment in our lives someday, if we consciously work towards it from the now.

On a side note, satisfaction or contentment isn't necessarily joy. Happiness is a transitory emotion, you can't feel it 24/7. On the other hand, the absence of sadness, regrets, pining, disappointment and pain will lead to self-fulfillment and contentment, which is the next best thing. Living a perfect life might be a myth, but some lives are certainly more perfect than others, and would be more fulfilling and satisfying according to our personality and being.

So, where to start? To find contentment, one doesn't find the ultimate purpose in a single aspect of life, but instead focuses on it as a whole, and works towards the major core desires in their being. Unfulfilled desires and regret often has a heavy burden on the mind, which doesn't allow one to be satisfied with life and hence live it happily without purpose. 

First and foremost, one must find a career that satisfies them, for to earn the fulfiller of our needs and wants, money, one may have to keep working for a significant amount of time in their lives. Even if one reaches a position where they don't have to work for necessities and survival, one may still find themselves bored and eventually rediscover to urge to do something productive and even want to make an impact, at least on the small visible world around us, leading them back towards a career. I wouldn't exactly say follow your passion, because sometimes we don't have anything we are so passionate about that allows us to make money too. I would recommend pursuing a career that is ideally balanced between its earnings and growth potential, interestingness to you and its compatibility with your skill set and personality. It may take a lifetime to discover it, but that's alright. Better get there late, than never.

And of course, a good work environment makes a ton of a difference. Having friendly and chill coworkers and a boss who is not a plain jerk can make people want to work even if the work itself isn't something they are highly excited about. I think Google knows that programming can get boring at times, and thus tries hard on all other aspects to keep its employees satisfied.

A factor related with career is hobbies. While its awesome to have a hobby that's the same as your career, the fact is that it still becomes a work/job and may eventually not provide the same amount of satisfaction to you later. Although its difficult to manage an additional hobby with a career, it is not impossible and it does pay its rewards. Most people enjoy having casual hobbies (even if it is watching Netflix or listening to music, that counts) and it would lead to lesser stress and more happiness compared to a life that is solely focused on your career.

Money isn't happiness, but the enabler of happiness. Financial security does lead to contentment, and spending your money on things that provide the maximum and long-lasting utility to you can lead to happiness. Impulse-buying often leads to regret and dissatisfaction afterwards, while deliberated purchases of goods and services are more satisfying to some. Bonus points if you had to work hard or save for it, and it turns out really worth the effort. Though that can't happen all the time, and thus tying up all your desires in materialism might lead to a hollow feeling inside, since the mind wants much more than things and fancier things to be content, even if capitalism may not want you to believe that.

I have to admit that a healthy relationship may be necessary for contentment, since we are biologically and sociologically wired to follow that path. However, they are but one aspect of life, and overly focusing on it often results in dissatisfaction. Apart from romantic relationships, good friendships and family also play a role in mental well-being, since they make up a significant part of our lives. For self-fulfillment, one must cut out the weeds that are poisoning the yard, and plant new seeds in their place. Those seeds may grow bad again, and one mustn't hesitate to cut them off, leave the land empty for a while and then try again. Such is life. 

To add to that, sometimes one can't cut people off, and sometimes indeed one shouldn't. While its near impossible to change people, even those who are trying and willing to, one can learn to live and adjust with the compatriots that life has given them. This may involve a combination of ignorance, corrections and outright confrontation(s). Everyone's a work-in-progress, on the same journey as you are. But if they are detracting more from your life than adding to it, its only fair you prioritize yourself and move on. You can't find contentment by endlessly trying to fix or change a person, and nor will you be satisfied if you have to change yourself very much in order to be with someone.

There's also the journey of personal growth or fulfillment. People can often end up wanting to try something new, or improve themselves in some way. Self-fulfillment purports that you must pursue your misc goals, such as learning a new skill, trying something new, improving physical fitness etc. if they provide satisfaction to you. This means you must love the process of working towards that goal, or at least be indifferent to it rather than hate it. This is the reason why people find it difficult to get fit, since diet and exercise is perceived as a (temporary) restraint. If you really hate the process and love breaking out of it, its impossible to sustain it in the long run.

There are two approaches to dealing with a personal goal that's getting difficult to achieve. Either one can commit oneself to the goal, come what may, and keep trying and evaluating different approaches to be able to achieve it. The other is when one realizes the goal isn't really worth it, and stops the endless cycle of demotivation, guilt, shame and torment, by focusing on other aspects and pursuing other goals that would be more fulfilling. There's nothing wrong as such with both approaches, one must just judge which is more appropriate in their context.

You must have noticed that I haven't added doing good, helping people, impacting the world etc. as a standalone factor in self-fulfillment. This is because I believe that in terms of contentment, doing good is only worth if you feel good about it. Morality can't be taught to anyone and everyone has different views on it, and hence in terms of self-fulfillment, one must make the moral choices that match with their conscience and internal values, so that they feel satisfied. This is why the term "constraints of virtue" exists, since some people may end up living such a moral, proper life that it doesn't agree with their mind/consciousness. You know where you stand in terms of good/evil, and where you want to stand. Make a conscious effort to move towards that point where you'll be content, even if it may involve a bit of selfishness and lesser goodness. Recognize that sacrificing oneself and people-pleasing may not lead to complete happiness and fulfillment, and its alright to pull back from it if it is draining you instead of satisfying you. 

Note, a basic principle of morality is that you can do what you want as long as it doesn't harm others, but if you don't believe in that, then...

However, perhaps the most hardest thing of all these things, is to be content with oneself. Yes, its good to find ways to keep improving oneself and become a better person, but there comes a point when some flaws just needed to accepted, not by anyone else, but by you. For example, though a lazy person may tone down on their laziness and find ways to become more productive, it will still exist and cause occasional lapses. And instead of beating oneself up, one has to accept that perhaps it might not be eliminated fully, since it may have become a part of their personality. One cannot remove all their flaws, but only find ways to work around them and reduce their impact on one's life. And issues such as mental illnesses, pain, trauma etc. prevent one from realizing their full potential and feeling good about their existence. 

I'm sure I'm missing out on other important things as well, human wants and needs are infinite. However, the common basic things seem to be a decent career and relaxing/fun hobbies, a healthy and satisfying relationship with people you care about i.e. friends, family, partner etc., actions that agree with your moral compass, even if it isn't pure good, and feeling comfortable with your own body and mind. Do people exist who have actually achieved all this, at even one point in life? I don't know. But we can still try, for the idea gives hope, and hope is what we all need to go on.