Some questions as a series newcomer

Hi guys, I've recently (a few months ago) started playing Guilty Gear (because I saw some cool Faust fanart on tumblr) and I really love it so far. But I do have some questions and I wanted to get some opinions cause Google wasn't super helpful.

1. Am I supposed to use the d-pad or the joystick for combos? I've been using joystick for movement and combos, and the d-pad for dashing, but I didn't know if that was right.
2. What's the recommended order to play the games in in order to get all the story as well as the fighting bits? I didn't know there was a storyline so I don't want to miss stuff.
3. Is there a good beginner's guide with a list of all the moves that I could easily refer to when playing? I'm still discovering moves and combos I didn't know existed lol. Thanks in advance!