I used the Kaplan course and used a lot of online sources to relearn stuff I didn't learn as well or just b/c I am old and don't remember it. I found Kaplan to be great for everything except QR.
I suggest studying 2 sections each day and not just go over one section. And to do as many practice tests and quizzes you can. It is all about PRACTICE! b/c it is easy to learn all of it, but applying it and doing it is what makes it hard.
I suggest using Oat destroyer as well, I never used it. But if I could do it over again I would have used the OAT destroyer as I felt unprepared for QR and needed more practice on Physics. And b/c I hear great things from it.
Also youtube has a lot of great videos if you are stuck on subjects, like organic,bio, chemistry,physics. It was a life saver.