Ive done several vendor shows over the years selling cupcakes and cookies bit all have been outside. I have the opportunity to do an outside event for a big 4th of july event. Any tips or advice on storing/selling cupcakes since it eill be outside and HOT

Buy coolers or make your own.  Buy big moving boxes in 2 sizes.  Put oine in the other, filling the space between them w/blocks of ice - just fz gallon fzr bags w/water.  Then wrap the boxes in foil, then heavy bath/beach towels.  Just put a items few out at a time for display maybe.   Mostly they should be wrapped....maybe in 2's & 1/2 dz. 

If insects and such are a problem you can get "food umbrellas" - they're thin enough that you can see through them but they stop insects getting at things.

Yes, food umbrellas are a good idea.  They are small.....you could probably get maybe 4 or 6 under one and you should be able to find them at a $ store.