What kind of charges can I expect for public intoxication and misrepresentation of identity by a minor?

Public intox is a Class C misdemeanor.  As far as level, it's similar to a traffic ticket in that it usually results in the payment of a fine and court costs.  This is the lowest level of misdemeanor in Texas.  If you don't have any other history, you may be able to negotiate for a diverted or deferred sentence.  Either option will help keep your record cleaner in the future.  If this is all they charge you with, then you're basically paying out some money and maybe taking a class to tell you not to drink.  Your bigger problem is if they upgrade the charge for your fake ID.  If you created or possessed a fake ID with intent to defraud another, the prosecution could charge you with "tampering with a governmental record" which is a felony level offense.  Again, if you have no criminal history, you could probably qualify for a diverted or defferred sentence.  Diverted means that you do some things to "rehab" yourself, then they dismiss your case outright.  There is no judgement to haunt you later.  In deferred's, you plea guilty and a deferred type judgment is entered which the public can look at any time--- however, you can petition the court later for an order of non-disclosure so that others do not have access.  Under either option, you're looking at one to five years on probation, just depending on the court your case falls in.  You will be required to pay a fine, court costs, and complete community service.  You may want to visit with a criminal attorney in your area to see if they can't get ahead of the charges.