Re: city block
Yes when you're in the part of a city that is set up (more or less) in a grid.
There are some short blocks and some long blocks. The larger the city and the more regular the street grid, the more uniform the size of the blocks.
Note that a "city block" means the entire area bounded by the four streets on each side. If a building takes up an entire city block, it's generally a VERY large buidling.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.