I wore my flip flops all day and inbetween my big toe hurts badly. Is this normal?

Flip flops. Very common when flip flops are first worn. The area between the toes is sensitive and can become bruised and the skin can even blister. The area toughens and may even form callouses as the flip flops are worn so it is no longer painful. I generally recommend wearing the flip flops for short periods in the beginning. This helps toughen the skin and tissue without injuring the area.
Maybe. If your flip flops have a strap between your toes it may have irritated the area or caused a blister.