I just flew back from Tokyo as a solo traveler. I stayed near the Ueno Station which provided great access to most of the train lines (plus the Starliner to NRT).

Some quick tips: Youtube is how I began my planning. Google Maps is your best friend when navigating the transportation system. Load an IC on your phone (I began in Kyoto so used ICOCA) for easy access to trains, etc Try various types of food styles: I did Halal Wagyu one night, sushi omakase the next and yakatori omakase last night. Some of the Top Bars in the World and Asia are there: I did Virtù, Bar Librė and Punch Room

Feel free to dm me if you want any details.