People love talking about themselves. Try to be interested in the lives of other people. How do you strike up a conversation? Ask them a weird question, there's lots of good ones on asklemmy. If you could swap lives with any fictional character what would it be? If you could shoot anything out of the tips of your fingers what would it be? What is a rational fear you have? If it's fun to you it'll probably be fun for others too.

A little philosophical here, but you're usually better at doing things when you don't care if you succeed. Try to make friends because you should try to make friends, not because you need friends. Talk to people because conversation is great, not because it's the path you must follow for friendship.

How do you know when it's okay to share stuff about yourself? Not a fucking clue buddy. I think most people out there are actually pretty bad at conversation too, so have patience with them.

Not sure if this has been helpful. I read a book once, Platonic by Marissa G. Franco. It's helped me understand friendship better.