I can answer most of that, though I'm not an expert. I might not get things 100% right.
Meteorites are regularly found with metal detectors, though it's much more often that people who aren't expressly meteorite hunting, have actually just found a piece of magnetite or other iron containing mineral.
Meteorites can be either pure rock, a mixture of rock and metal, or pure metal, and the metal itself is generally mostly iron and some nickel, though other metals do occasionally show up in them.
Meteorites can be found literally everywhere in the whole world. A place to start, from what I've heard, are your own gutters. Just take a strong magnet to the gunk in your gutters and any metal that flies out and sticks to it could be a micrometeorite. It's not entirely guaranteed, pollution has been found to be another source of small metal particles ending up in the air, but if you're in a rural area it's less likely to be pollution.
Hope this helps
