As a new driver you won’t be able to tell much and probably wouldn’t know why you felt what you did. A bigger decision is whether to buy new or used. If you can get some support then new from the local kart shop may be the biggest factor. I wouldn’t expect too much support from an individual on a used kart.
A cheap way to get some hands on is to help others at races and test/practice sessions. Just work it out ahead of time. That will help you decide on some things like what kart stand to by. I can tell you being solo in the pits has it’s challenges.
Renting a kart may be an option. It can be a bit overwhelming at first. The LO206 is a nice staring point. Do not mistake that for being easy. Some aspects of it are easier, but it just make the other stuff more critical.
Yesterday a new guy showed up looking to get into karting. He told me this is the first thing he is ever doing that and not jumping in head first. Sounds like a smart approach
By all means keep asking questions. I you can avoid any pitfalls it does help enjoy the sport better. I am pretty new to karting myself.