In the States the 211 service should be able to give you info on your local options as well as food stamps/EBT. The more destitute and challenging your current situation, the more benefits you’ll be eligible for, IIRC.
That said, the wealthier areas may very well have unlocked/unguarded dumpsters, but getting there without being harassed by the local pigs is the obstacle there. I mean, that’s one of their main jobs: keep whitey happy.