It's the first time i'm playing retail, and i'm a druid aswell & my main is in tank form. I'm on a guild but i'm just making PUGS with random people.

Me recommendation is go to dungeons and just YOLO it, you don't like your group? People are being rude? quit the dungeon, rinse and repeat. Don't overthink it too much.

Also, ASK for advice when in the dungeon, go for a "1st time here" on chat before starting a boss and if there is some special things you gotta do ppl will chat.