How to find friends on discord?

I've been on discord for a while now, but somehow I didn't quite understand the system. Do I just go to any sever and then talk to people or does it work differently? And where can I find such sever where people talk about Minecraft, for example? To be honest, I'm also quite shy and would be afraid of simply going into any language channel without knowing whether I "may" do that at all.

You can also just write on Discord. Find server? I think there are certain websites for that. You can often find Discord channels through YouTubers (mostly Gaming Youtubers.