At the beginning of the game, you get a good amount of starting resources, and as you complete quests, you will earn even more. To get things up and running quickly, follow the quests and just build and upgrade all your base buildings as soon as you can.
You will reach a point where you will actually have to start saving for new buildings and upgrades, and that is the moment to slow down. But until then, just spend like there’s no tomorrow. And before you know it, you will have your own dragon to fight by your side.