Having trouble coming up with something to draw? No worries - while you'll eventually learn how to start from a tiny seed of a thought and gradually nurture it into a complex concept to explore through design and illustration, it's perfectly fine not to be there just yet.
For now though, here's an idea that might interest you.
Fantasy Ice Cream Cart
Fantasy worlds are great. They've got magic, they've got swords, they've got quests and everything in between. But you know what they don't have?
ICE CREAM! What an oversight! What a travesty! But that's okay, you're here now, and you can fix it. Figure out how one could reasonably operate a cute little ice cream cart in a world without refrigerators. You can certainly use magic, but the more over-engineered the solution, the better!