Your English is excellent… you should be very proud 
I think if you are aiming for a full rpg click to move with varying landscape and varyingly accessible areas… Id use an entirely different approach with a full character movement component and navigation mesh. This way you have control over where your character can go, set movement speed, acceleration which can vary easily according to your characters level.
By the way, here is how get velocity now works, combine it with vector length node to get… you might also use get physics linear velocity node … Get Velocity | Unreal Engine Documentation