You can find the following currencies in Mythic Legends:
Gold: the standard currency in the game. Gold can be earned by opening Chests, completing Daily Challenges, or progressing on the Battle Pass. Gold can be used to upgrade Champions and Legends, and unlock new ones.
Gems: the premium currency which can be purchased in the shop. You can also earn extra Gems via Daily Challenges or progressing on the Battle Pass. Gems can be used to purchase Gold, Chests, Champion and Legend cards, or for rerolling Artifacts.
Tokens: earned by participating in Daily Events, Incursion Events and the Adventure Event. They can be used to purchase items in the Token Shop. Additionally, you may receive Tokens when you make a purchase in the in-game shop. Event Tokens are only valid for one week, after which they will be automatically converted into Gold.