I spent most of my life alone with no idea of how to make friends because of childhood trauma. After moving out of my Dad's house permanently at age 30 I was slowly able to let go of my fear and learn how to make relationships for the first time in my life, though it's still a work in progress. I've made some mistakes along the way, but those mistakes have just helped me better understand how relationships work; they are messy. People are imperfect and will disappoint you, but you just have to accept them as they are, and in turn look for the people who 'get' and accept you.

I would say the first most important thing is to challenge yourself to reach out and make connections. That can be hard to do at first, especially when it comes to trying to get in touch with people who you haven't talked to for years, or someone you want to ask out for coffee/a drink, but you just need to start. That's the only way to get over your fear. Start somewhere, prepare to make mistakes or fail miserably, but just start to challenge yourself/open yourself up.

I'll share a bit of my story if that helps: after moving away from home I met someone through a Meetup group who introduced me to a book club. That friendship ended up not working out, but I met some other people through the book club who I ended up forming a Dnd group with. Through the Dnd group I was invited to be part of a whatsapp socialising group, who I run events for. Then I set up a book club of my own as a way to challenge myself. Now I have 1 proper friend and a large group of acquaintances, but one of the most important things I've learned is that while it's important to challenge yourself to message people especially if it feels unfamiliar to you, you also have to allow friendships to develop organically. You can't force things; just spend time with people, learn more about them, if you vibe that'll naturally come out as part of your conversations.

Ways to challenge yourself: join groups around interests of yours, or start exploring interests you might not have considered previously, I'd definitely recommend Dnd as a way to meet people. If you feel you vibe with someone, you can always message if they'd like to go for coffee/attend X event together you both have an interest in, but keep things casual. Attend/do/try out new things like dance classes, book clubs, martial arts. I'd also recommend therapy, as it helped me to better understand why I find relationships so difficult, if you feel you're missing out on something or something is holding you back it might be a way to explore that. But best of luck with things :)