For your scooter ride, kick start to get it up to speed first, then press on the throttle near your right thumb to accelerate. Familiarize yourself with the speed first. To ride safely, squeeze the brake to slow down when needed.
For bikes, before you get on, adjust the seat according to your height.
To adjust the seat, loosen the bolt on the stem below the seat. Lift the seat until it is approximately even height as your inseam, then tighten down the locking mechanism on the seat stem. Make sure you’ve adequately tightened the locking mechanism to prevent the seat from falling or twisting while you ride.