If you're homeless in NYC, there used to be a squatter scene in the Lower East Side. That's changed over the past decades, but ABC No Rio at 156 Rivington used to be a squat, and they have a calendar of open events on their web site. Bluestockings books on 172 Allen St., one block south of Houston Street is open all the time and is not really squatter-oriented, but has people and flyers associated with this scene. Food Not Bombs moved out of ABC No Rio to the Catholic Worker at 36 E. 1st street, they serve free food in Tompkins Square Park after 3:30PM.
Also, 2600 meetings happen on the first Friday of every month in the lobby of 153 E 53rd St, people start coming in at 5PM. They're technical people who might be sympathetic to someone in your situation.
If you look on Craigslist, there are a lot of (Microsoft) desktop support jobs. Some need an A+/MCSE, some don't. It sounds like you could handle things more complex, but if you're in dire need it's a paycheck. Also you have some experience doing that. Do that, learn that, try to save some money up.
In fact if you're homeless you should probably look for an easier to get job like a messenger's job first. Then I'd look for desktop support job. If I was homeless I would put aside learning ML in R until I was getting a steady paycheck and had a roof over my head.