You need to go to the track nearest you and find their class structure.
Most tracks/clubs have classes that will favor a particular motor, ala Yamaha, Rotax, TaG (IAME, etc), PRD.
There will be a progression from lower power to higher power, smaller chassis to larger.
Sticking with the same motor is supposed to allow one to have a more cost effective path to progress through the classes by adding/removing restrictors on intake, exhaust, etc.
How old are you and what general area do you live in?
Do you know where the nearest kart racing track is?
Have you been to the track on race day and asked this question of the race director and participants? You’ll find karters to be exceptionally helpful, especially with the introduction of the sport to newbies.
Good luck, it’s a great sport!