Just got invited to play for the FIRST TIME...what now???

Hello! I figuredthis be a good place to ask. So I've never played DnD, but have heard if it and today I got invited to play by a group because they're starting a new campaign

They know im a complete noob but...ugh Im so nervous??? (Social anxiety doesn't help)

I have about 6 hours to prepare - what's some good stuff to watch/read for a beginner?

The only character that comes to mind rn is a ranger (as per DM's suggestion) with amnesia who's obsessed with the unknown and magic, because they believe it can cure them

Is that good enough for a first time? Ughhh Im so nervous haha