What does it mean when you have red marks and it hurts on the roof of your mouth?

Many possibilities: May just be trauma from crusty bread, chips, etc. May be herpes virus lesions. May be infection. Other possible conditions. Usually it is trauma. See your dentist for evaluation.

See your dentist: Red and painful spots on the roof of your mouth could be a sign of different things, which is why it's a good idea to see your dentist. No one can diagnose without examining your symptoms in person.