Will they charge me with my 2nd DUI or both and how much time can I do or what should I do?

You are possibly facing a year in jail on the 2nd DUI [priors increase the penalties] and revocation of probation and return to jail on the first DUI. No humor intended: if you can't do the time, don't do the crime. When charged with any crime, the proper questions are, can any evidence obtained in a test, search or statement be used against you, can you be convicted, and what can you do? While this isn't a 'capital case', it certainly carries potential time, so handle it right. No amount of free 'tips and hints' from here or elsewhere are going to effectively help in a legal defense. If you don't know how to represent yourself effectively against an experienced prosecutor intending to convict, then hire an attorney who does, who will try to get a dismissal, charge reduction, diversion, programs, or other decent outcome through motions, plea bargain, or take it to trial if appropriate. At least your BA was not over the legal limit, but the officer still arrested you for under the influence because of your driving and FST failing performance.

Some depends how old you are. If you are under 21 .04 is enough to convict. If you are on probation you could be given up to the maximum of 6 months on that case alone.