Sounds like you need some basic gravity code! You'll need a variable to store Vinnie's vertical velocity. When Vinnie jumps, set it to a positive value, when Vinnie is in the air, decrement from it slowly and, when Vinnie hits the ground, set it to zero. Every frame, update Vinnie's height by adding the upward velocity to his position.
I don't know if you were actually asking for help, but I like helping people! Good luck making Vinnie jump!
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