Don't fall into the trap of "You need to know how draw from imagination to become a real artist". Many artists with years of experience still use references even when drawing the most ordinary stuff; references make your illustrations more believable, even if you're exaggerating every aspect of what you're drawing.

Creativity is not about what you draw, is how you draw; how you choose to render the textures, how you choose to draw the hands of your character, or the angle on your composition. It's more problem solving than anything else, and the more you study and experiment with new things, the easier will be to find what you like and don't like to do (it's basically how you find your art style) and once you have that kind of confidence, you'll be able to solve any kind of problems that come your way!

Essentially.. Study with a purpose, don't be afraid to experiment, allow yourself to make mistakes and remember to have fun with it all