Networking starts by talking to people!
Also, it's often taught as this innate trait people have-- "personable" or "a social butterfly", versus someone "shy" or "quiet". But people skills are very much SKILLS! They aren't innate. Some people have more natural talent for it, sure, but it's something you can learn, train at, and practice. It's something you can get better at!
And the best way to learn how is to actively practice. So talk to that person at the bus stop. Talk to the people in line at the grocery store. Start conversations, and practice your people skills!
(This is coming from an introvert who had to overcome social anxiety and habits learned from trauma to actually do it, but I want to reassure you that you CAN overcome your fear of talking to people! The more you practice, the more it builds your confidence too, not just your skills.)
For anyone who wants to learn how: here are two books I'd recommend reading. 1.) How to Win Friends and Influence People by Dale Carnegie. 2.) Everyone Communicates, Few Connect by John Maxwell. These recommendations could be helpful even if you have people skills but want to hone them, too!