I have searched for some answers but thats all i could find is WalkSpeed = 0
You could modify the default PlayerScripts. You do this by going into a new place, play solo, look at PlayerScripts.ControlScript.MasterControl.KeyboardMovement. You have to copy the scripts you wish to change into StarterScripts, then edit them. Lines 110-114 is where KeyboardMovement binds the controls.
Alternatively, you should be able to use ContextActionService and you should be able to unbind the actions that the KeyboardMovement sets up.
game.Players.LocalPlayer.PlayerScripts.ControlScript.Disabled = true
Use in LocalScript to disable movement. Set Disabled to false to re-enable it.