Is solving quizzes with friends considered cheating if they do not count towards college grades, and is a female student who reviewed the answers of an information test, whose grades do not count, sinful?

The reference for knowing what is permissible and what is forbidden is the educational system. If the system prohibits seeking help from others in solving quizzes before the exam, then it is not permissible. If it allows it, then there is no harm. As for looking at answers during the exam, it is forbidden cheating, and one must repent from it. The fact that the exam does not affect grades does not make cheating permissible.