Well hello!
Here's a bit of starter (returner?) information to help you along:
It's a completely different game now. Later you will run into Aurum Vale and Cutter's cry as well as Garuda and Ifrit again, but they are small fry now! SO many primals

.
There are no fire parties, do this quest and unlock the challenge log as soon as you are able
https://ffxiv.consolegameswiki.com/w..._the_Challenge because LOTS of Exp comes from it every week.
MSQ will get you to 70 easily, just do it, you have like 400 hours of story to get through, story is not great until higher levels and gets amazingly better at HW expansion. Do your beastmen dailies as they give you access to nifty mounts and minions among other things.
Actively learn to play your class, I recommend you level your crafts for self repair and +100% to gear wear (use challenge log, guild leves and grand company turn ins as well as beastmen when you are higher lvl) and try to find a FC with nice people who don't mind if you ask questions.
Have fun!