I'm excited for you that you're going to have these new opportunities!
Really, I'd say this is about figuring out what ways work for you, uniquely, and that you like, to make friends in the context of the kinds of social opportunities college can provide.
You say you want to go places to hang out, for example. What kind of places seem most interesting to you? And what ways of just meeting people tend to feel like best fits for you?
You also mention you have trouble trusting people and struggle with PTSD. Are these related? Have you ever gotten any pro help with either or both? Would you be interested in looking into that?
What do you feel like you need to start being a little more trusting and building trust with others? When you say you pull back from people as you start to get close, any sense of what seems to get you to that point?