A contract signed by a minor is voidable (can be cancelled without penalty) by the minor, but is not void (legally inoperable as if it never existed). HOWEVER,

A contract signed by a minor is voidable (can be cancelled without penalty) by the minor, but is not void (legally inoperable as if it never existed). HOWEVER, if a contract is cancelled, both sides must return anything they received the other side party to the contract.