Well, if you're able to manage to get money for a smartphone, and maybe see if you could get one of the most basic plans with data, then you could download several apps, such as Postmates. This app is a food delivery system, you don't need any kind of transportation, and you could walk or even use public transportation to deliver food. I do this and I find that it typically pays a little better than US federal minimum wage before tips, when you calculate it out to an hourly rate(they obviously don't pay you per hour, but I calculated it out to per hour and that's about the average).
You won't have a boss, or co-workers, and you're always accepted as being a postmate so long as you pass a background check. If the reason you can't work is because of a felony, well unfortunately, and I don't mean to sound rude, you're going to be practically screwed. Having a felony charge against you is impossible to deal with. If you have one, my suggestion is live in a different state, and if that doesn't work, then try a different country.
Thing is, you will need a bank account, but usually most banks let you open a checking account for free and you just need to maintain having deposits in it yearly.
Anyways, there are probably other apps like that one too. Unfortunately UberEats is more strict and they require more things in order to sign up with them, though postmates is the least strict of those apps I find.
Some ways to get money to be able to afford a smartphone with a basic plan in addition to food you need:
1) Find bottles throughout the day and go to a recycling center and recycle them
2) Creative Begging:
Hold up a sign that says you won't vote for political candidate A if you get some money(regular begging doesn't work, you have to be creative with begging). Be sure it is a conservative candidate if your area is liberal, and a liberal candidate if your area is conservative. (I've seen multiple videos of people doing this and it working)
It turns out that, also people are more willing to help people who do NOT look homeless. Weird right? If you happen to have nice-looking clothes, like an old suit or something, wear that and keep it in good condition. Hold up a sign that says something like you need to pay off a large amount of debt and anything can help. People are, surprisingly, more willing to help someone who looks rich than poor(I know it's counter-intuitive, but sadly, that's how society is: they're more willing to help a bankrupt former wealthy person than a poor person). If you don't believe me, look up some social experiments about it.
If you don't have any nice looking clothes, try some other creative begging along with recycling, and save up to buy a suit from a thrift store. Thrift stores usually sell suits for under $20.