Many homeless folks band together and form community, though it's tough because it's often ripped apart by the state.

One good point is that Roma people share an ethnic identity, whereas the homeless in the US are the poorest and most in need across a whole set of ethnicities - though disproportionately the marginalized, as the function of marginalization is to make these violences, like being unhoused, tolerable to the rest of society. So Roma face a fundamentally racist and genocidal attitude directed towards them (a decent amount of their tradition of traveling is due to being forced out by various Euros - forced to adapt to that status quo).