Yes. We usually use it as a measure word and say, for example, “a block of chocolate,” “a block of ice” etc. But you can use it by itself as a noun too.

Exactly! A block can also be a street or the part of a street. I’d say it’s mostly used in cities. Some examples: “My best friend and I grew up on the same block.” “My cousin lives a few blocks over from here.” “The theatre is 2 blocks from my apartment.”