Gold can be used to purchase items of clothing, emblems and talismans as well as the Battle Pass (1200 coins) and custom games (2000 Coins) which comes with the limited edition robot item and 25 roses.
Roses can also be used to purchase items and spin the Golden Wheel for 30 roses. These are the received roses. You can buy roses for 25 gold each but they can only be given to others. You can exchange these roses with other players or send a bunch of roses to everyone.
Your are able to purchase roses and gold in the shop with in-game purchases. You can earn gold and roses by watching ads in the wheel of fortune, win gold in loot box and in ranked mode and if the servers are in maintenance and you already have the plunger hat.