Well welcome to the forum!
I have good news, this question has been asked As many time as there have been new owners, you’re not alone.
Rather than answer it all over again, I’ll point you to some previous discussions:
And I’ll point you to this thread which is full of suggestions for “what to learn first”:
You’ve got a lot of reading ahead of you! Get a snack and a drink and dig in, you’ll be glad you did. 