I started betting on sports recently, but I'm not good at everything. I thought I might ask for some advice here. What should I pay attention to?

Hey dude, what's the problem? You should at least write what is going wrong, so that I can suggest something to you. Overall, I recommend looking at https://www.dimers.com/bet-hub/mlb/schedule because it's a respectable site. There is a lot of useful information for beginners here, as well as a good list of bookmakers to work with safely.