To disappear, never move to a small town. Never move to a big city. Cities just under 100,000 are big enough to remain anonymous but small enough to exist on cash and few documents of record. Always rent a place from a couple on a handshake. Plenty on Craigslist. That doesn’t exist in huge cities.
I do live in a small town (about 10,000 or so), but we moved here as empty nesters. We’ve found that when you don’t have kids in a school system, it’s harder to meet people. As a result, we only know our neighbors and some people from church. I bet in the entire state of Indiana we only know a few dozen people. Good enough. My only downfall is that perfect strangers seem to think they know me from somewhere else. I just have one of those faces that seems familiar.