I'm in Tokyo right now
Travelling here is actually quite easy as long as you grab a copy of the Tokyo Metro map which shows you all the station and lines and a map of Tokyo's central ward.
The subways have English on their signboards and the trains have English announcements.
Most popular places around the city can be accessed via the subway which you can pay 710 Yen for a 1 day ticket on the Metro Line or 1000 Yen for Metro + Toei Line which lets you travel on additional lines (tho not necessary to get Toei lines unless you intend to go to the outskirts of town).
Most of all, plan ahead on the places u want to visit so you don't have to buy daily tickets too much. You can practically spend the whole day in Shibuya or Akihabara shopping so a one time ticket is usually enough.
Going for a boat ride on the Tokyo bay tomorrow before taking the Shinkansen back to Osaka