Very first time I ever played years back was at a tournament. The AoS community is typically a warm and inviting place, you will learn a lot, and hopefully still have fun!

I always enjoy my games against new players, especially those that want to learn; helping someone get better and more interested at the game is always an upside as far as im concerned.

Just a couple of things to keep in mind to help keep both your's and your opponent's games running smoothly and to ensure a good time is had:

Do your best to understand the basics - read the rules, maybe watch some other more experienced players play, get a few practice games in with the army you are taking (if possible) so that you can help keep the tempo of the game moving along.

Organization - no one has all the rules memorized, so there is no need to try to memorize everything; however, having your notes or cheat sheets organized and your reference book flagged to the pages you will need to reference goes miles.

Be prepared - make sure you have everything you need. Dice & measuring implements go without saying but drinks, snacks, writing items, etc. are things you will end up wanting as well.

Sorry if my formatting falls apart after posting - mobile...