There are thousands and thousands of discord servers you can join without any invite. Try searching disboard.org to find a server for your game, or check YouTubers descriptions, many have one you can join. You're not the only person I've heard complain about discord being difficult to learn. It does get easy, especially if you can find someone to help you join a voice chat or something.
Depending on the game you might have built in chat. I have made friends with random people I gamed with, and we continued for years.