I never joined a class for ipcc as well. They are not a necessity to clear exams. I have mentioned the books that i referred, most of them cover questions from the practice manual. But ensure that you practice every question from the pm, previous few years questions and rtp because that makes you more confident about the kind of questions that may be asked and the format/ language in which icai expects its students to answer questions. You still have a good amount of time even if you have started nothing yet, so do not worry, stay positive, believe in yourself and stay away from people who try to terrify you with their horror stories about some relative / friend of theirs who took many attempts.
Accounts and advanced accounts - PC Tulsiyan
Law - Munish Bhandari
cost & fm - Padhuka
audit - Surbhi bansal
it/ sm - Dinesh madan
tax - manoharan
You can view podcasts at studentslms.icai.org in case you get stuck somewhere. Try your best to cover all chapters as ICAI can ask any chapter for any number of marks that it wants.