We've got a GMC Acadia (2017?) and the AC is pretty slow to blow cold which is issue 1. I have zero AC experience and not sure if there's anything I should do or try before taking it into a repair shop. I have basic tools, no AC pressure testers or anything I've read a bit about. 

Issue #2 is the driver's side is always warmer than the passenger side, even if the controls are calling for driver cooler for the split. There's a mixing valve that I assume isn't working in the dash somewhere?