#1 is battery storage (listed AH) if you plan to use it to commute . Make sure the scooter can do 30% further than your trip. multiple reasons.
#2 is being safe. a horn and lights are the best for cars in front of you
Behind you most cars will not see the tiny brake lights on most scooters. also not many scooters have turn signal that would notify the car behind you that you will be slowing down.
#3 is power. Being able to speed up is more helpful than slowing down when trying to avoid an accident. This is rated by Watts and volts. Below 48 volts is a kids toy.
Something in the range of 600-800 watts 48-52volts with 15-21ah would would have a long distance, speeds over 32kmh and do a 30% incline easily.
350 watt 42 volts is safe for ages 14 and above
dual 1000 watt , 52v is considered advanced rider
Anything with 1200 watt 60 volts and above is pro rider
And Ah determines how far the battery will go before it needs charge.
18 ah on a dual motor scooter with 1000 watt motors gets about 50 km running one motor at lowest gear