Im getting one of these for my daughter, i read that it has an adjustable speed limiter. Does anyone know how it is adjusted? thanks

On the throttle you will see a screw with a nut locking it in place. That's what you adjust to govern it.

thanks, also if you know, it idles high, i havent had a chance to look at it we are picking it up tomorrow but is there a common problem that I should look for thanks

The choke could be on, the idle may need to be adjusted. The carb may need to be cleaned. That's where I'd start.