You need a handful of resources in Dragon Ball Z: Kakarot to increase your character’s powers and unlock new abilities. The biggest resource you need is Z orbs, which you can locate through several different methods in the game. The other resource you need to find in the game are D medals, and they’re a bit more troubling to locate in the world.
The most straightforward method of earning D Medals is to complete side story missions. These are the blue missions available to you, and they typically involve fetch-based quests you need to complete for a character. After you’ve completed them, they give you a series of rewards, and one of them is usually a D Medal.
The alternative method is to go out of your way to find them in the world. They’re scattered around the game much the Z Orbs, but they’re a bit more hidden. You need to go out of your way to find them. A great method of locating them is to use the Search for Ki ability. In this mode, you can see where a D Medal is hidden, even if you cannot directly see it. You can see it from pretty far away, too.
There’s a set number of D Medals on each map. You can see how many there are when you open up the world map and hover over any of the locations. You can see in the bottom left above its name how many D Medals you found and how many there are in total. Because of how many side quests you can do and how many you can find in the world, you should have plenty of D Medals throughout the entire game.