Lucky 13 is a great bar close to downtown with the best burgers I’ve ever had. Market street grill is great seafood and also has a bar.
There isn’t much of a tailgating scene. Although it is getting a little better. I think (think being the operative word) there is a visitor tailgating lot where alcohol is permitted. But they will definitely enforce it if you try to bring it in the stadium.
Provo does have a couple bars on center street - which is a decent hike from the stadium but Uber can get you there easily.
Hope you have a great time (but not too great! 😀)