It's been a few years since I visited Tokyo (before covid), but what I still remember is (in no specific order).
Akihabara (electronic store district)
Tokyo Tower
Samurai Museum
I'm not sure where this was exactly, but I also visited a few hobby stores that had a lot of modelling equipment and items that are not common here in Europe.
These are the ones that come to mind when I give it a quick thought. If you have time, I would also have considered a trip to Mt. Fuji. I was unable to get there due to a typhoon that hit while we were in Tokyo.
In addition, I recommend going to a higher-cost restaurant and getting a wagyu taste menu. This is undobtly what I remember best from the trip.
Also, navigating the Tokyo tube can be challenging due to the lack of English information, but it's manageable and a cheaper and faster way to get around Tokyo. With the new translation apps that are available today, I would strongly recommend one that can translate Japanese text from images to make life simpler if you want to take the tube.