Small question about arrival

Hello travelers, I have my first trip in two weeks, and I have two doubts, that I want some help

When you arrive to Japan (airport) do you need proof that you are bringing money?? Example like a 1000 USD and then exchange it.

I have a trip from Tokyo to Hiroshima, how long before should I be at the airport, so I am comfortably with times and don't end up losing the flight?

by whiplash73