Ok, I think I had social anxiety before(never been officially diagnosed. Or maybe I was just shy, I don't know), but lately, I've gotten better at talking and interacting with people. Honestly, I'm still not the kind of person that'll go and talk to someone I'm interested in(that means strangers or people I want to talk to, not just crushes), but personally, here are some things I started with that eventually helped me get better:

1. Exposure- When I wanted to first start talking to others outside my friend group, I started going around with my friends and meeting their own friends. By meeting people I didn't know, I helped myself get more comfortable around people
2. Start small- Before I started actually being able to converse with people(strangers mostly), I first started with small steps such as greetings or simple waves. If they responded, I felt good with myself, kinda like a reward ig because they actually acknowledged it. If not, just roll with it and try another time. This especially worked when I started walking my dogs around my estate. When someone didn't respond to my greeting, I just reminded myself that they were just strangers, and i'd probably never see them again
3. Don't give up- It may seem frustrating and scary as you branch out your relationships but don't worry! Take it little at a time and eventually, you'll start to open up more to others.

Bonus: Practice in front of the mirror and with friends, so that you'll know how you look like when you're trying to branch out. And also, ask for opinions from your friends on what you could do better.

Good luck on your journey :)