What do you think washington meant by "the first years in our new life"?

Most certainly he was reffering to "our new life" as an independent country from England. The first years are always crucial for a new society that will begin to experience its own constitution, laws, customs, etc. Whilst it is a challenge, it also is an opportunity to establish clear policies and ideas for the greater good. At the time United States declared its independence from England, Adam Smith had recently released his book "The Wealth of Nations", in which he remarked ideas of freedom and laissez-faire, laissez passer, french words that mean "let do, let pass", fostering the liberty of man towards entrepreneurship.

why do you think kush in nubia is not as well-known as egypt?

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.