Well, the first step would be to contact Admin. He has a google spreadsheet where you sort the type of rarity a card is in the booster pack. He will explain the details if he needs help about this and will explain the rarities. I don’t know how many sets he needs done.
I guess this part of the site explains some way to help too: https://forum.tcgone.net/t/contribution-guide/26 .
Hope this helps.