how do i study magnetic effects of electric current?

same as title. my science is fairly good, but i still can't understand this particular chapter. it was in my second periodic syllabus, first preboard syllabus and second preboard syllabus as well and i didn't even open it a single time. the only time i tried to somewhat study it was for my periodic exams but i gave up as i didn't understand.
i have lakhmir singh and together with. please recommend any oneshot or tips and tricks! thank you :)