So I read a lot of Peter Parker fanfiction, and he is canonically broke. Worse if he loses his support system. But the way that people signify poverty isn't really accurate as someone who had lived in nyc. Here are some things commonly written wrong:
So heat is normally not regulated by the unit. In most older buildings the entire building is radiator heated and from October to April that shit is on and HOT! Now slum lords do exist, and there might be a few days here and there if the landlord doesn't care where a building doesn't have heat. But normally maintenance lives in the building they work on and that means they don't have heat either. And New Yorkers are resourceful people and best believe that they will not let their kids, grandparents, family, etc. sit in the cold for too long. The heat will be fixed one way or another. So as long as he has any type of shelter he is warm. And with his skills Pete can break into any apartment that's empty for a night or even a stairwell. So the image of him freezing due to poverty is wrong.
So unless Peter is too proud to ask for help, there is food available. Not only would the people he helps offer him food, food offering is a huge love language of multiple cultures especially among the poor, but there are so many food banks. Literally hundreds of food banks, he could hit up multiple and meet his caloric needs. Going hungry would be a matter of pride, no house, very possible, no food, not realistic.
The visibly homeless are normally not JUST homeless. As someone who has been homeless, more than once, looking homeless normally means another health condition on top of homelessness. There are so many gyms for public showers, you can get toiletries form the dollar store, and those same food banks will often have self care items as well. So if Peter can access an empty unit or a gym, which we totally think he can, he will be able to clean himself. He might not have alot of clothes but think of how many you would need on a carry on, he could carry a backpack and no one would know the difference. Also, there are laundromats everywhere. For pretty cheap, cleanliness would be possible.
The actual weight of poverty.
A lot of it is the cost of housing and mental. For the poor, 50 or even 60% of their income could go to rent. Saving is impossible. Small luxuries like phones or clothes are often cheap in comparison. You are often moving from one crisis to the next without any safety net. You get sick, so you miss work, so you are late on rent. Or you have to decide on meds or a bus pass, and everything is slower or harder. A lot of times, you can do everything right and still get screwed over by things outside of your control. The stress, the fear, is constant. And you are constantly being told it's your fault for not being good enough. Cook from home from scratch to save money, but hours at multiple jobs and long commutes leave you exhausted. You're supposed to be this perfect poor person, but it's unrealistic.
Real poverty is exhausting and feels hopeless, but it isn't normally cold and hungry. Not in the city for a super hero anyhow.