1998 Chevy 2500 A/C was working just fine, stopped for a bite to eat with my family and when I started it back up the A/C would not blow on any 1,2,3 or Max settings. Can anyone give me an Idea on what I should troubleshoot first? Thank you

. Check all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

. Spray control buttons with WD-40. Grime from your fingers sometimes prevents the switch from working. WD-40 cleans the switch.