This is key for newbies.
Warning for newbies: I'm a confident person that is very good with tech, but initially, I found Discord confusing and the threads a bit daunting to insert myself into.
The only way is to jump in the deep in and say hi...
And you might need to do that a few times if people are in the flow of a deep or really silly conversation.
Good luck to all you plankton!

^{What's a plankton? asks the newbie...}