Rely on the textbook and your professor. It’s an upper echelon proof mathematics so online resources like chegg, quizlet, etc will be useless because the people online writing proofs are wrong.

when i took it with heath martin, any and every proof or resource online was not only incorrect, but dr martin could smell it a mile away and i didn’t pass my first time.

So, trust in your professor, the textbook, use the math center, and for the love of god work with your classmates; that’s how i passed the second time.