I DID live on the streets for several months. In fact I was the ONLY homeless person I ever met who was really homeless. There is always a shelter, a home or even a motel or apartment, ONCE you are willing to play the game. And, the game is usually to start taking psychiatric drugs; after you agree to accept the prescriptions, all sorts of doors open to you... at least in DC, Virginia, Montana, Maryland... that is all I know of.
As far as being armed. You are NOT supposed to be armed in the shelters in most cases. Church shelters don't require psychiatric treatment criteria usually.
Street people in Montana that I lived with for about 7 months called it "passing the Wing-Nut test" that is seeing a shrink, getting adjudicated as mentally ill and then accepting the Prozac, Zoloft, etc. After that... food, shelter, money, dentistry, glasses, and all sorts of support was available. In DC, it included lodging in hotels and apartment buildings in pretty nice sections of town, after getting the psych drugs of course.
There were a lot of street people that were armed, probably all of them. Many carried butcher knives. One common stratedgy I saw was a large kitchen knife along the outside of the weak forearm, often held there with an ace bandage, some masking tape or a couple of shoestrings, etc.
Another common weapon I saw was a stick with a very large nail or two driven through and then the stick taped or tied on both sides of the nails to keep the stick from splitting. Often this was a piece of broom stick or a piece of shovel handle, etc.
In Montana, most carried guns. Many carried backpacks and one whole class of railroad riding vagrants carried 30-30s with sawed off stocks and barrels and short handled 3/4 axes as well as pistols. In DC areas many carried old .38s or derringers of some sort.
Those without weapons often carried a milk bottle full of urine, feces, draino, battery acid, etc., to be thrown in the face of an assailant.
Each area has several different stratas of "homeless" and there are groups and subcultures and each shelter has it's own type of person to some extent...
Just be careful out there. And, more than anything else... speak little if any. Listen and look a lot. Stay in condition ORANGE at all times. Find a safe place to sleep. Stay alert, especially when and where you sleep... IF you are really mixing with the "homeless". If you just plan to work and sleep in a shelter (and I saw a lot of college kids doing such things) and help out at meals, clean up and stuff like that... that is fine but it is NOT being a part of the sub-culture.
The most dangerous thing I saw in the "homeless" subculture is the rampant psychiatric drugs, mixed with street drugs of all sorts, alcohol and paranoia along with fear, and a few scattered hard-core criminals.
I stayed alone, ate in one or two shelters only and only church shelters. I met several street people who proved to be more aware, not on drugs of any sort, and who were willing to partially take me in as a student. However, even those who were willing to be closest to me never really trusted me and neither did I fully trust them. BE CAREFUL...
In general, the REAL "so called homeless" are nearly all on mind altering drugs, armed, fearfully dangerous, and criminal to some degree... do you really want to be part of that culture on purpose????
