What I linked is specifically about running this sheet on this platform. Keep in mind that this isn't a sheet written by Roll20 (most sheets here aren't), but by someone in the community that wanted to run that game system. The sheet author as well as others contributed to the page I linked for you. If it helps you learn how the sheet works, great. Otherwise, you are looking at getting a pro subscription and building your own sheet, or looking elsewhere. Whatever you decide, may you find a way to run your games.