Welcome;

There have been several threads (several years ago) about NYC survival/bugging out--- you may be able to pull them up with the search function.

One of the things that came up was the issue of walking out of the city, or at least Manhattan.

A couple of things that I recall receiving favorable mention were a silcock wrench to open the external water faucets on buildings (to get potable water)(NYC water is pressure fed, so water flows even if the power is out) and the utility of the common and ordinary (in NYC) 2 wheel shopping cart to carry your things. It avoids you having to carry that 50 pound back pack, and, being so common, draws less attention than a big backpack. Living in the city, you may have one of these already. Last time I was in Brooklyn, you could find them all over for very reasonable prices.