Every now and the I read where someone asks what he or she should do in photography, as if running out of ideas is what's consuming them. My advice -- start a project -- something long term, and see how your approach and your depth of understanding changes as you become more engaged in a project. It doesn't have to be unusual, trendy, or arty. Pick something that you'd like to know more about, something that you might be afraid to try, a subject that means something to you personally, a topic that might be socially enlightening, or maybe something that has to do with nothing more than a favorite color. The point is to start something and see where it takes you. At the heart of art is an inquisitiveness, as art and science sometimes overlap, it's the search for meaning.
For years, I have been interested in the backsides of buildings along "Main Street" in small towns. It used to be that people lived above their stores or businesses, and in many places, one worked very close to where one lived. Today, that's not often the situation. but where downtowns thrive, it seems that people also live in apartments above the businesses. The backside of a building tells me more about the uses of that building than the storefronts do. They tend to be more utilitarian, and also show something about the inhabitants as well as the businesses located there. Documenting these "backsides" has been a long-term project and something I try and do when I have the opportunity to visit a town. Like many long-term projects, I don't know where it will end up, but as the saying goes, "The journey is the reward."
Try your own long-term project and see where it takes you.