Hey!
I think you wanted to say "what does it mean"
When you say "Get over it" it means that you want the person you are talking to to forget something that happened to them. It is usually used in an emotional sense. For example if I did something to you and you didn't like it, and you were still complaining about it long after it happened I would say "get over it." It is sort of an immature thing to say to someone.
"get over with it" doesn't mean anything.
hope that helped!