>>242
>how much it cost to get a travel ticket?
Depends where you are from and the time of the year. Expect between 700 to 1200 USD for a round-trip in a good scenario
I paid well over 1000€ just to go to Japan from Europe, but bear in mind this was before tourism was allowed and I didn't book with much of an advance
>what level of japanese should I know?
Although just relying on English will not get you very far, Japanese people are used to tourists, especially in big cities like Tokyo, and even if they only speak japanese, they will try to help you as they can. That being said, I advise you to know some basic expressions before hand, such as "ありがとうございます", "すみません", ... and to always have a translator app ready, to scan text and such
>how to get internet there
There are many companies providing SIM cards. Some even include a phone to use as a hotspot (since some phones outside Japan don't deal well with Japanese SIMs) and you can pick it up straight from the airport, in the provider counter
There are also many places, such as metro stations, convenience stores, shopping malls, ... etc, that have public hotspots
>how to find an hotel or sharehouse?
I'd say you can rely on the usual Booking.com and Airbnb
>how to have a card for trains?
You can get a PASMO/Suica card. Check their websites for better information
https://www.pasmo.co.jp/visitors/en/
https://www.jreast.co.jp/multi/en/welcomesuica/welcomesuica.html
>how to exchange money in japan?
The same you exchange it anywhere else in the world, you can go to an Exchange Center or withdraw at an international ATM (7-Eleven Bank usually works)
I recommend getting a Revolut card and exchanging the money to Yen before hand
There are also some machines that you can insert money and it will exchange for you
I hope this was insightful anon. If you have any more questions shoot
Do you already have something in mind? Like places in Japan you'd like to visit and when?