Here are a couple of things to consider when using an attendant joystick.
First, be sure to keep your body in a position so that the wheelchair cannot accidentally roll over your feet! And, wear sturdy shoes.
Second, driving with an attendant control can be done very proficiently, but is a sill that must be learned.
Third, most wheelchairs have modes that allow the sensitivity of the joystick to be reduced. I know this is available on Permobils. Each of mine has modes that will make the wheelchair go very slow, which effectively reduces the sensitivity of the joystick.
It is also worth pointing out that the location of the attendant control can make a difference. Be sure it is set up so that it is comfortable and safe to use with your dominant hand.
Steve