Building a network is something anyone can do. Join meetups. Find local user groups. Find online groups and get active in them. Give talks. Write and publish your thoughts locally and/or online. Talk with people. Ask (good) questions. Let people get to know you and the way you think. Many more ways exist than just these.

Connecting with other professionals in various ways is all there is to building a network and anyone can do it. They just have to do it.

This. I'm still benefiting from being in a BSD users group that I went to between 2000-2008 because it was filled with passionate/talented tech people, most of whom have gone onto other things. Find places to get into discussions and show your opinions and have discussions. If you are in a group where your mind is never changed, then find something else.

Ok, now that's advice.

You definitely can.

I always built my network mostly at local meetups and online communities.

It helps if, like in my case, are into functional programming, as people into that niche prefer working with other functional programmers.