New and confused

Hey dear community.

I am super new to the game, a friend introduced me to the game and I mostly play with him. But whenever I go and do something alone I feel INCREDIBLY overwhelmed.

I play as astrologian (started arcanist and then scholar) and I feel stressed out in the dungeons whenever the tank does a bigger pull. Most of the time I manage to keep all alive but I don't do any damage because I am so overwhelmed :( this is my very first MMORPG ever and until now all people I encountered were super nice and gave advice. But I wanted to ask you when does this stop? Is there any useful and spoiler free guides on how to improve? What was your beginning like?

Also I had some weird encounter with a guy who fought some lvl 42 fate monster or something and I joined in and helped and he spedrun trading with me, gave me 10k gil, emoted and then flew off on a FAT moogle Ballon hollywood-swing thing. I was so confused haha

Please feel free to share such stories with me :)

Thank you all