Choose a project that looks interesting to you (ideally with a large community and modern tech stack) and join their Slack/Discord/Mailing List. You'll need to be patient and humble and it's going to take a while until you feel really comfortable, but read a lot, ask questions and try to contribute small bits here and there.
This will put you in touch with many interesting and experienced people, plus it's usually a great learning experience.
Here are some ways:
1. Join local Meetups: There's no substitute for offline communication.
2. Join Online community on Slack/Discord/IRC etc: Pick your favorite tool(programming language, framework, libraries etc) and get involved on Github, StackOverflow.
Also, you need to balance the relationship. How do you add value to their life is something to ponder about.