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.
Flora is Fauna
Spring has sprung and on the Planet of Flowers, the line between plant and animal does not exist. You have two options. You may design a creature based around a particular plant of your choosing, considering how it moves around, what (and whether) it eats, and how it defends itself from other predators. Remember - plants generally gather their energy through photosynthesis, so consider whether your creature needs the usual assumed elements, like a mouth or a nose.
Alternatively, you might explore how this might impact creatures that traditionally eat or harvest from plants. Bees, for example, might have adapted in a wildly different manner from those here on Earth, if their flowers were prone to... fighting back.