Writing 200 words every day is simple, but it's not easy. For most people, the hard part is finding a topic. After writing for 120 days consecutively without breaking my streak, I feel qualified to give bits of advice regarding this matter.
Just like everyone else, there were days when I lacked inspiration. Truth is, I was just not creative enough: everything is a potential topic, but few feel exciting. The good news is that 200 words are quickly scribbled once you stop whining. The voice in your head giving you excuses can be shut down. Two cases: you either have things you must write about or not. In the former case, just sit down and do the work. Otherwise, any topic will do.
Great cooks can amplify the savors of common ingredients to create a unique experience. The same goes for writers. Pick an object, a human being, an event, an idea. Find analogies. Trace it back to a first principle. You have to distort reality. To sublime the banal to make others think and experience.
Writer's block? You are probably not experiencing enough. Get rid of your creative limits. Look with fresh eyes. Touch with pure hands. Smell. Taste. Hear. Go back to your inner child. Let your mind wander. Polish your observation skills. Awaken, consume life to the marrow, and you will never run out of topics to write about.