Self Study GED

Hi everyone out there 😫 I’ve decided to get my GED but bc of money and my work schedule I wanna do self study, looking into GED.com I saw there’s classes but they are expensive 🥴 can anyone help me how to make a study plan (I have 0 idea or knowledge about the topics on each test) or where to study for free or at least for cheap classes? Thank you so much!