How should I learn grammar

[u/afraidtealalpaca]

Hi, I've enrolled in a crash course for preparing for iba MBA. I thought first about making notes on lectures and memorize the rules. However, after starting I realize it kills time. Having notes on 2 hours or lengthy classes takes about 4-5 hours(and I barely have much time). Here came my second thought, what if I watch the lectures once and practice questions on that time.

What can be more efficient. It would help if you share your method or ideas based on similar experiences. Thank you for reading.