Everyone has dreams or goals or desires. Everyone has something that he or she would absolutely love to achieve. Problematically, we don't always know the "correct" path to walk in order to achieve those goals. This, however, is not necessarily important. When beginning to write a poem, I will generally have an idea of the concept I want to write about, but more often than not, what I end up with is not what I started with. This is okay. It's called the journey, and it leads to discovery. But let's get back to the prompt at hand.
I want you to think about something you really want to achieve. I don't want you to care about the how or the why of getting there or what you want to achieve; I just want you to have a solid picture of a goal in your brain. Do you want to make more money? Do you want to find love? Do you want to make a new friend? Ask a girl out? Ask a guy out? Be asked out? Win a competition? Something, anything so long as it is something you want. Got that image in your head of what you want? Good.
Now, write from the perspective of already having achieved this thing you have in your mind.
How does it feel? What are you doing? Let your mind go, and let your emotions wander with it. Write about how you feel now that you've successfully achieved this thing you want. Be creative, have fun, and write!
Good luck and have fun writing!