Good for you for thinking about building your credit the best way possible.
First tip is that you don't want to run up debt. So, it is not so much about how much money you spend, but how you manage your use of credit.
You can build a strong credit history by responsibly using credit. That means using your card, paying your bills on time, and not carrying a balance that eats up more than 30% of your credit limit. It is best to pay the balance in full, so you don't pay interest, but use your card regularly.
Use your card every month, even for a small purchase like a tank of gas or one trip to the grocery store. This will show creditors that you're taking out a debt and paying it off.