alpha gear
 

I can not rename anything
assigning numbers did nothing
as you can see, all is grey in this area only, can not drag things here, do not know if you can

I assigned 1 2 and 3, but hitting either number doesn't change anything

I'm doing something wrong here and can't figure out what

Left click on the left most box for the equipment or the action bars. It will highlight, then you choose the number you want.