HELP!!

idk if this is the right spot for this buuuttt ima post it here anyways cuz theres alot of ppl here anyways so i bought gold premium and i see everyone having gold guns how do i get an 8th slot so i can get gold guns?

you have to buy 8th slot guns on G1 or have a promo code

so do i just buy 8th slot guns an automatically get 8th slot or buy 8th slot and then buy weps?