A little bit of advice that will help you when you go shopping:
- White shirt with black studs and has small pleats
Spend the money to get one made of 100% cotton, not a cotton/poly blend. Or, if you must get a blend, get one with as little polyester as you can. There is a real and noticeable difference in comfort. (A 100% polyester shirt is kind of like dressing in Saran Wrap.)
- Air force pins to replace the studs
When you go to the kit shop or wherever, what you're looking for are shirt studs. They probably come in a set of four or so. If they're not too expensive, consider buying two sets so you'll be able to carry a spare. Depending on how well they're made they can sometimes break, and of course such breakage will only be discovered at the last minute...
You can wear plain gold ones or ones with an approved branch or regimental pattern. Unless you're in the Air Operations Branch, the ones you're probably picturing when you say "air force" are probably not correct for your branch.
Plain ones have the advantage of never turning upside down, as ones with a badge or crest can do.