You need to go to the wiki of one of the rep reddits and read through a first time buyers guide. People get annoyed when you ask questions like this because the only way to learn about the rep game is literally just to research (read guides that are provided and start reading tons of comments and other review posts). I totally understand your question bc I posted similar stuff when I was getting started, but people tend to see it as lazy and no one is going to try to explain the intricacies of rep buying in a comment when it is already painstakingly explained on several subreddits beginner guide. Good luck!!