If you want beaches you can go to Ocean city, MD Chabad has food but you are probably better off bringing your own food.
There is a Hilton and Marriott there. (Hyatt was supposed to open up soon but they were delayed).
Phoenix has some nice pools and kosher restaurants
Myrtle beach is a popular beach destination as well but no kosher food.
The main beaches are in Florida (which you want to avoid) HNL and LA/ San Diego