If you can't think of anything interesting to write, you can use story prompts to get your mind moving. You don't have to write a full story about these silly story prompts, but they can at least help you get your pen moving and give you inspiration to write something else phenominal:
1 Stuck in a Storm
Put a group of random people together, and they have a storm keep them locked inside for longer than they'd like. The more diverse the group, the funnier the story will be. They might all be students at a university. They might be women trapped at a book club. This is one of the story prompts that can take off in several directions, so it's all up to you.
2 Blushing with Boy Bands
Live out your wildest fantasy by writing a story about a girl who gets to climb on stage with her favorite band member. Maybe the character will sing on stage with them beautifully, or maybe she'll trip and sprain her ankle. Whatever she does, make sure that it's interesting. You wouldn't want your readers to get bored.
3 Hometown Heroes
Have your main character become a hero in an odd way. Maybe she rescued a kitten from a tree. Maybe she found a way to stop world hunger. Maybe she didn't do anything at all, and the newspapers got their story wrong. Whatever she did, now she's famous, and she's trying to cope with the situation.
4 Exploring Space
Even if you've never written a science fiction story before, you should try it out. Write about a planet that is similar to Earth, but contains a different species. This way you can let your imagination run wild. Anything is possible in the reality you're creating. Try to make something up that you've never seen before, so that your readers will be enticed by it all.
5 A Joyless Job
Have your main character get stuck at a job that she absolutely hates. Maybe she's there, because her parents are forcing her to work. Maybe she's there, because her crush is there, and she wants to get to know him better. Despite her reason, she hates the place, but is unable to find the courage to quit.
6 Animated Animals
Your main character doesn't always have to be human. Write a kid's story about a raccoon that is trying to find a new place to live after its home was destroyed. Have it meet a human that wants nothing to do with it, and almost runs it over with his car. Have it talk to the human, if you want. Do whatever it takes to get your readers to fall in love with that raccoon, and root for it.
7 Underwater Adventures
Your main character is swimming in the ocean when she sees something sparkling at the bottom of the water. She swims toward it, and ends up finding something unexpected. Maybe it's a new sea creature. Maybe it's a rare gem. Maybe it's an entire underwater world.
When you have writer's block, you should force yourself to sit down and write. You don't have to write anything serious, which is why these prompts are a perfect way to get your brain moving. Are you a writer? What do you tend to write about?