To learn the aerial arts you do not need any fancy accessories.  In most studios they have what you need to get started.  However, as you learn your particular weaknesses or fears it is good to know what accessories are out there to help you overcome.

Gripper gloves are one of those inexpensive tools that can really come in handy when you need them.  They are not for practice all the time, but they work really well on the days you need a little extra grip, or when you are learning a new skill and need to take you grip out of the "fear equation".