Use the search bar up the top mate! Anything you need to know will be there.
Or, right up the top there's a "Wiki" section which is guides and tutorials on many things. But, your probably have your boost restricted in 1st & 2nd gear, as well as limited (maybe) to 112mph. The boost restriction on 1st and 2nd is a simple 1 minute job of swapping some silicone over. Have a search your find out how! and, welcome!