when can you report somebody for scamming? is it on the act of doing so or is it when it is done? perhaps a few people would say that i just don't have to be stupid or anything but why does some people try to make fool of some people who are a bit stupid or newb.

If you're careful, you'll report it before getting scammed. If you're nuB, you'll report after being scammed. Now figure out, what should you do.

You really should try to screenshot things first and then go through it. That way if you get scammed the person won't get away with it, because you have proof.