I have a stomach ache/fever and im want to go to the beach tomorow!!?

If you have the flu, then none of them will help. The flu is a viral infection and it can last days. Advil might make you feel better for while but if you are sick then you are sick. If you have a true temperature over 101, then going to the beach might not be your best choice. You can get very dehydrated very fast in the sun. It would be a good idea to talk to your parents if you are not feeling well.