Air compressors are dime a dozen. I got mine at Harbor Freight and it works for me.
Hers a couple good sites:
https://usaairbrushsupply.com/
https://spraygunner.com/
I'd check out USA Airbrush Supply and compare prices with Spray Gunner. Both are good sites.
Another useful thing to get is an airbrush cleaning station to clean/flush out your airbrush. Harbor Freight has them super cheap. This is what I use:
https://www.harborfreight.com/airbrush-cleaning-bottle-68154.html
$7 bucks is a steal…
Whatever airbrush you decide on, make sure the hose from your compressor can fit your airbrush. If it doesn't, go to UAS airbrush Supply site and get an adapter. They have a wife variety to fit most brands of airbrushes.