They're there for your first year, they give you your first beer (Dionysus)
When you get your heart broke, (Aphrodite)
they're there for your worst year
Don't get you at all, but your apple don't fall too far from 'em (Camp Half Blood/Camp Jupiter)

They own too much wicker (Demeter) and drink too much liquor (also Dionysus)
You'd wash your hands of them, but blood's always thicker (demigod siblings)
You might look just like 'em, that don't mean you're like 'em
But you love 'em (Connor and Travis Stoll)

Family is family, in church or in prison (Zeus and Kronos)
You get what you get, and you don't get to pick 'em
They might smoke like chimneys, but give you their kidneys
Yeah, friends come in handy, but family is family

They're there when you're married, divorced, and remarried
You fall out of touch, but then someone gets buried (demigod life spans)
And you're right back together like no time has ever gone by

Can't live with or without 'em, you might talk about 'em
But if someone else does, well, then you'll knock 'em out 'cause
When it's all said and done, they're the only ones that you got

Family is family, in church or in prison
You get what you get, and you don't get to pick 'em
They might smoke like chimneys, but give you their kidneys (Hephaestus)
Yeah, friends come in handy, but family is family

Yeah, family is funny, they'll ask you for money
Even though they know you ain't got no money
They show up at Christmas, get up in your business (the Winter Solstice)
They might not be fancy, but family is family

You might look just like 'em, that don't mean you're like 'em
But you love 'em

This song feels like it's talking about demigods and the gods. There are so many similarities, I just put the names up in the lyrics (the bold). Those aren't part of the lyrics of you were confused about that.

Some of it sounds like the Olympians just saying that they're stuck with each other for eternity. It's hard to explain down here, but just try to listen and think about it. It makes sense