Just like in Europe. It's the same normal international data plan for most carriers (I've done it on At&t and Verizon).
And you get cash from 7-11 (yes I'm serious). American cards very very frequently don't work. Especially in any sort of machine, particularly vending machines and the train ticket machines. Many atm's won't take american cards either. But, every single 7-11 (which are everywhere) has an atm which takes american cards. They sometimes say 7-i, or Seven and i holdings. It's all the same thing (7-11 is actually a japanese company, and they are everywhere). Other than 7-11, every Post office should have an ATM that works too, but they are way less common.
The train stations are absolutely insanely huge, but the signage is usually pretty good. There is almost always the latin spellings of the train stations and things. So getting around isn't too scary.
The other side of this coin is that there are quite a few different train companies in Tokyo, so sometimes you can be in the "JR" part of a station which is totally different than the "KEIO" part, or the "Tokyo Metro" part. The big stations are the worst for this (like Shibuya, Shinagawa, Ikebukuro, Tokyo Station, Ueno, etc). The exits always have numbers, and usually you can find a map that says which exit goes where. It's definitely confusing though (also, because some of the stations are so huge, it's very possible to be in a completely different part of the station than you've seen before, so having been before doesn't necessarily help navigating the second time.
It's a bit confusing. You basically can just think of them as cents for the exchange rate. (¥100 is $0.96 right now). The smallest bill is ¥1000 which is about $10. There are ¥500 coins and ¥100 coins too, you'll see these a lot. The atms seem to give out ¥10,000 bills, which is basically $100, I've never had a problem getting change, and everyone is super polite, it can be a bit stressful though to have a credit card which doesn't work and a $100 bill, especially if you just want a snack.
Also, you'll frequently see both the ¥ symbol and 円. They both mean yen, and I think it's the difference between "$" and "dollar".
They're kinda interesting. Basically none of the drivers speak any english in my experience. It's very hard to tell them where to go (even trying to say the name of a place in japanese). They are quite expensive, but they are everywhere. If you do decide to get in one, the driver has a lever to open the door, you never need to do it yourself (and you leave it open when you get out). I've only taken a taxi in tokyo a few times, and it's an experience, the trains are easier to navigate.
There is uber in Tokyo now. The prices aren't nuts and it seems a bit easier to communicate with them (and you don't have to navigate payment which is awesome). Most of them are actually taxis (there are Uber taxi for normal taxis and Uber Lux for fancy taxis, as well as black cars).
Narita Express (NEX) to Tokyo
First, you'll need to find the train at Narita. It's a big airport but it's fairly straightforward. The main train system in Japan is called "JR" which is always spelled out (not japanese). You'll follow signs that look like this:
The train you want is the Narita express. You're cards will not work in the ticket machines, you need to go to the service center to buy a ticket. This is good anyway cause the stupid ticket machines are very confusing (you can buy a ticket to anywhere in Japan on them). The ticket office looks something like this:
You will ask them for a Narita Express ticket to the station closest to where you are going. The tickets are assigned seating so they will give you a specific train to catch.
You can also get a Suica card at the ticket office. This will get you around on the subway all over tokyo. You can probably get a ¥3000 yen one, but around tokyo most subway rides less than ¥500 from what I remember. You can refill it at the stations too. You can use suica at tons of vending machines and small shops too. :)
They will tell you where to find the trains, but it's very nearby the office. The train does split on it's way to shibuya, so make sure to set where your ticket says. :)
You'll see options for "green class". This means first class. I don't remember there being a huge difference in comfort and you don't get drinks or anything. There is a deal for foreigners for a 1 way Narita Express ticket for ¥1500 for normal class. It's quite a discount so seems good.
One thing I've found is that it's very challenging to listen to announcements in Japanese and pick out the station names, but on the Narita Express there are digital signs that tell you which station. The trip to Tokyo takes about 90 minutes (Narita is faaaaar away). You might be tempted to take taxi, but it's probably not worth it. A regular taxi would probably be about $250, and Uber is flat rate at about $400 (¥40,000).
