You shouldn't have to bend over to use them, or you won't be able to look ahead comfortably. Think about the amount of weight you'll have on the scooter and decide whether it will support you. Most are designed to hold between 300 and 350 pounds. Test-drive the scooter. Make sure you feel like the scooter is something you can brake and steer.
Many kick scooters use a rear friction brake instead of hand brakes on the handlebars.
Decide which you are most comfortable using. Most kick scooters have a relatively small deck that might not have enough room for both of your feet to rest on, especially if you wear size 13 or larger shoes. One foot is pushing the scooter most of the time anyway. But you can buy a wider deck that will allow you to get more of your feet off the ground. Don't make sudden and erratic moves in high-traffic areas.