A/N: sorry I didn't do this earlier

[ 1 ] Darth Vader is Luke Skywalker's father. (There's your big basic)

[ 2 ] Obi-Wan Kenobi was friends, a mentor to Anakin Skywalker (who is Darth Vader) before Anakin joined the dark side and is famously known as Vader.

[ 3 ] Movies in order (Original - Prequel)
O R I G I N A L
1.) A New Hope (1977)
2.) The Empire Strikes Back (1980)
3.) Return of the Jedi (1983)
(All the Star Wars movies are numbered in Roman Numerals. The first three movies are the first in the order. But the prequels are numbered 1,11,111 | Roman Numerals |. So you watch the originals, then prequels)
P R E Q U E L S
4.) The Phantom Menace (1999)
5.) Attack of the Clones (2002)
6.) Revenge of the Sith (2005)

IN ORDER OF STORY:
4.) The Phantom Menace (1999)
5.) Attack of the Clones (2002)
6.) Revenge of the Sith (2005)
• Rogue One: A Star Wars Story (2016) - Plot: To steal The Death Star plans. Which you see Luke and the rebellion pilots in 'A New Hope' ready to destroy The Death Star.
1.) A New Hope (1977)
2.) The Empire Strikes Back (1980)
3.) Return of the Jedi (1983)
• The Force Awakens (2015) - Decades after Return of the Jedi

[ 4 ] Princess Leia and Luke Skywalker are Twins. Leia is the younger twin. Their mother is Padmé Amidala who is the Queen/Senator (leader) of Naboo. She is the wife of Anakin who joined the dark side (Darth Vader)

[ 5 ] Han Solo & Chewbacca are best friends. Chewbacca nicknamed 'Chewie'. Han can understand Chewie's language because he grew up with other Chewie's (called Wookies) when he ran away from being a slave at a young age.

( hopefully this kinda help you guys :/ )