What to wear to a concert, undressed overdressed!!! HURRY PLEASE?!?

i now this sound stupid to ask but i may be going to my first concert and i dont want to be underdressed but i dont want to be over dressed? its attack attack, breathe carolina, and a few more bands...what should i wear?!?! like a causual dressss but cute or like a cool tee and skinny jeans??