In terms of food what I loved about japan was wandering down random alleys in tokyo and finding some little hole in the wall sushi or ramen place. Guarantee the people inside don't speak a single word of english but the best sushi i've ever had.
I like their snacks a lot too, they're not big on sugar and I find american snacks are way too sweet
If you're a tourist they have a deal where you get unlimited rides on the shinkansen for I think 1 week for $200 which I'm pretty sure is less than the cost of a one way ride normally. Did that to visit kyoto, osaka and hiroshima
Definitely recommend learning a few basics phrases in japanese if you're going outside of tokyo. You'll run into lots of people that literally don't speak any english, or at least pretend not to. I guess it shames them to speak poorly so they just pretend not to speak it at all.
IDK why being white is a problem. Japanese are racist against everyone but they'll still treat you with respect and you'll run into lots of women there that like american gaijin