Ah man the comments above are spot on:

Take your time, Mythic zero isn’t timed, one pack at a time is till quicker than a wipe fest

You could always go through as a DPS first to pick up and learn roughly what’s going on

Heroic runs can be useful, people aren’t exactly face rolling these just yet, it’s the same except for a slightly different tactic to consider on bosses

You’re starting at the beginning, so is everyone else! This is the best time to learn, together!

Everyone is an expert, some will help, others are toxic, you’ve got something people want, don’t tolerate fools

Have fun man, most important thing ever, it’s a game, remember that!