I didn't read all the replies yet but I wanted to add my experience.
First exchange for Japanese currency before you leave. Unless making an expensive purchase ($500+) you can't use your cards. Cash is king.
Second if you plan to travel anywhere order your japan rail pass while in the US. the JRPass is for 90 day passport visitors and it will be very helpful if you are going to ride the trains. Unlimited train riding all over the country even on the bullet trains. This must arrive at your home address before the trip.
If you hold a US government ID card like a CAC you can stay at a hotel in downtown Tokyo called the New Sano (Sanno?) anyway they took debit cards spoke good English had the Air Force Network on TV. It was a nice breather, but I only stayed there two nights.
Akihabira was awesome. I also went to the Square Enix HQ they have a store outside with some cool stuff for sale. With the Train pass you can probably extend your travel range. See Kyoto, Hiroshima etc. If you plan a whole day of moving about Tokyo make sure to buy the day pass for the subway, it's way cheaper than a bunch of short trip passes, but the train pass can probably get you everywhere inside Tokyo just a little bit slower than the subway.
Also all stores will have little trays to place your cash on, don't physically hand the money to them it's considered rude. When I needed more cash ATMs worked fine with my USAA debit card, but USAA is used to out of country transactions so make sure your bank is good with this.
I mostly stayed in Osaka which was amazing. Kyoto I visited the nightingale floor castle which was cool and the oldest Buddhist temple in Japan. I went into the mountains about 4 hour train ride north of Tokyo to the famous Fox Sanctuary, no one up there speaks English so it was an experience. The Hiroshima Peace Museum was really cool and not overly guilt trippy, it definitely provided information that is not taught in American schools.
I avoided places like Mt Fuji simply because I wanted to force myself to visit Japan a second time. Google Translate app was pretty good about 70% ish at translating signs at tourist attractions.
I was lucky enough to have two close friends who had lived in Japan for 5+ years each teaching English to be my guides often, but even when alone in Japan it was relatively easy to communicate. If I was lost and needed a Taxi or something I would type the English into google maps for where I wanted to go and show the results (in Japanese) to the driver and had no issues with that.
Oh also 100 Yen is roughly 1 USD so those 500 yen coins are 5 dollars don't shove them all in your pocket and only use bills to pay for things... took me a week to realize I was change hoarding like I do in the US.
If you get a chance to see Sumo wrestling it was really cool, but I did it as a group activity with several of my friend's co-workers.
Every restaurant I ate at had pictures of everything on the menu so it was easy to pick food without reading. Good luck and have fun. In regards to the train to Kyoto, I think it's about 3 hours on the super fast train, but the trains stop at midnight so if you started early and caught the last train back to Tokyo you could have a full day in Kyoto, which in my opinion was the second best part of my trip. The best was the Fox village, but that's an even longer day of train riding. I had to stay the night in Sendai because the tiny village of Shiroishi was out of rooms.
Edit: I think this is the site I used https://www.japan-rail-pass.com/
I was in Japan for like 16 days so I bought the 14 day pass, but the 7 day pass is 250 per person which is cheaper than 1 round trip train pass to Kyoto and back and you can use it ALL OVER THE COUNTRY. Seriously its made for tourists it was awesome. Only caveat is if a bullet train (shinikansen?) is full of normal ticket paid people you can't use your pass, but I rode many bullet trains and never had them say a word to me. Also the pass you get in the mail, I forgot was like a voucher and then in japan you go to the rail people office (should be many of these in Tokyo) stand in line for like 10 minutes and they give you the actual pass to get on the trains, this might of required your picture being taken, I forget. It was a very simply process.