Hi and welcome to the forum. I do play MP and here are a few pointers:
1) Make sure you have a clean sheet when loading - clear cache and load it fresh - i.e. do not go from single to multi player. I don't know why, but if you don't you'll likely lag/time out/desynch and everyone will get incredibly annoyed with you
2) Be prepared to play a tiny minor - New Zealand is a great place to start to observe. Even bigger minors (RAJ/Brazil/Mexico) require quite a bit of skill and knowledge, so avoid them else you'll just have a lot of angry players at you
3) Save the game periodically so you can reload it later and see what everyone is up to, what template they build, how they're scaling up industries, etc.
4) Make sure you have a discord set up and join the game's discord. Be honest about the number of hours you've played and that it's your first MP - people will cut you a lot more slack if you do.
5) Follow instructions by your "leader" (usually UK for Allies, Germany for Axis). It can be a little tedious, but it's part of the learning process.
6) Be aware a lot of games can go toxic - there's a lot of nasty players out there (sadly), so if you can play with friends, that's great, but if not, don't take any abuse personally, just mute the offenders if you want.
7) Meme games (non-historical) are usually more relaxed than competitive historical ones. However, you might get destroyed early by a major wanting your land/bases/resources. So take your pick.
8) Finally, watch a few twitch videos first. It should help.
PS: Make sure you have 5+ hours to spare!
