ac wont come on at all what could be wrong with it and what can i do to fix it

Most ac issues are due to a leak and low refrigerant. The first step is seeing if the compressor is coming on. If it's not look over fuses but expect to hook up gauges to see where the charge level is. If you don't normally work on automotive ac you will want to bring it to a shop. Use this link to find a good one near you. https://repairpal.com/repair-shops Alex