Cat bite punctured skin, kinda crusty. Infected?

See doctor. First of all you need a tetanus shot if you haven't had one for 5-10 years. Cats have relatively "dirty" mouths, meaning they have a lot of bacteria on their teeth, which get injected into you when you get bitten. Even if your tetanus immunization is up to date, you will likely have to see a doctor, who will determine if you need an antibiotic.