Is there any ifNot.Grounded command?

Sorry, but I don't think you know how anything works at this point. isGrounded isn't part of UnityEngine, it's a boolean variable from an example script.

Read the Unity scripting reference "cover to cover," and look up anything you don't understand in a C# / JS reference elsewhere. You are a long way from making your own game. (But don't let that discourage you!)

$$anonymous$$iloblargh, I just wrote is.Grounded ins$$anonymous$$d of isGrounded, that doesn't mean im that far from making my own game, because this one will be very, very simple anyway so everyone can do that :)