Food stuck in wisdom teeth extraction site. need some advice?

Flush out: If you were given a irrigation syringe you can fill it with water and gently flush out the area of food. If not you can go back to the doctor (there should not be any more charges) and they can do it for you or give you the syringes. If it isn't bothering you a lot you could wait and it will eventually resolve on its own.

Irrigation: Rinse with tap water. Use a syringe to irrigate. If you can't get it out. Go back to the surgeon who can flush it out. If it's not bothering you, it will usually dissipate spontaneously.