Tokyo is the second largest metropolitan area on the planet in terms of urban landmass. It also attracts about 12 million tourists per year. One of the most top visited places on earth. Tokyo is known to be one of the most clean cities in the world. There are several places where you can eat like Ichiran, Shibuya it has 5 stars rated on tripadvisor.com with over 1,000 positive reviews.
For entertainment you could go to Tokyo Disneyland because who doesn't like Disneyland you can always have fun at there even if you're not a kid. There is so many other things you could in Tokyo like visiting the Pokémon center, china town, imperial palace.
One thing you should know is that a US Dollar ($1) is equal to 92 yens in Tokyo. Tokyo is a place with crowded streets as you're walking around to anywhere, however it is a beautiful place especially during night because of how lit up it is.
You're experience at Japan will not be a bad one because anything you do in Tokyo will always be fun, like trying out new foods, seeing how different their lifestyle is compared to ours, and not to mention all the different entertainment like the Pokémon center which is just an amusement park but it's a beauty to Pokémon geeks like me.