Hi Erin! Welcome to SR! You can be an athiest and still go to AA. All that AA asks is that you believe in a "power greater then yourself"! It could be anything. You are the only one who knows if you are an alcoholic or not. That is your decision. I know my admittance to that and going to AA have changed my life for the better.
Stick around!
Hugs to you,
Missy