Ac blows hot air where do I start

Most folks would start by assessing whether or not the compressor under the hood cycles at all. If it does, you could have a low charge or a temperature control problem inside the car. If it does not cycle on at all, you could have an empty system or a low charge or an electrical issue. You could have a compressor clutch that will not engage. You could have a restriction in the system - some debris from worn out parts. Honestly, there are quite a few things that could be wrong...so...you have to start with a good diagnosis from a well qualified technician, preferably with Hyundai experience, and EPA section 609 certified for refrigerant handling. Good luck! -Dave