I am heading to Tokyo in less than 2 weeks. It will be my first time in Japan.

I like to explore new cities on foot, so I purchased a street map of Tokyo (Borch), but I am very confused. Most of the streets appear to have no names. Only the major avenues do.
I searched for some info online, and I read that blocks in Tokyo have numbers; streets do not.

The problem is that my map does not even show the numbers of the blocks! It would have been helpful to have this information handy, as it would serve as a rough guide for where I am if I get lost.

I guess my questions are:

(A) Can I find my way around Tokyo by sticking to the major avenues that have names?

(B) Do these major avenues have street signs that are written in Roman characters, or are they in Japanese?