app store not working

hi, i hope someone can help, but recently something went wrong with my mac, so i erased the disk and reinstalled the os after which the mac apple store doesnt seem to work. i launch it, but nothing happens, a windows opens but is greyed out (literally nothing but a rectangle, no text..nothing) and after 1-2 seconds the spinning beach balls appears. i have tried many things including: reseting the time, signing in and out of my apple ID, and even going as far as to reinstall the OS 2 TIMES. it has come time that i actually need to install something but i cant now. any advice?