There will be questions as to how you got the alcohol. If you bought it with a fake ID, this is another misdemeanor. If you solicited someone else to buy it, this is a misdemeanor and is more serious. You can lose your drivers' license or at the very least you may have to wait longer to get your license.

If you have applied for a guaranteed tuition scholarship for college in Arizona, you will lose this scholarship for the use of alcohol.

How long a misdemeanor stays on your record depends upon whether you are actually charged, or merely picked up and sent home. (This depends upon the arresting officer, and may depend upon whether you are actually very very drunk, or merely have a beer in your hand.) It depends upon whether you are a juvenile (under 18) at the time of your arrest, or are an adult. It depends upon whether your record stays clean following the arrest.

These are all the legal things. There are lots of extra legal things like how your family and friends feel when they know you've been cited with possession of alcohol, and whether you get anyone else in trouble at the same time you are cited.