Regardless of the brand or model, I would first go into Google and search, "brand Metal Detector, model xxxxx, review" just to see what you come up with. Can't hurt!
I have 2 years of metal detecting experience. Really find some awesome shit sometimes. Not sure how it works in America, but here in Europe I prefer going to known medieval trading places, around old roads or 1-2 feet underwater beach level. Also sometimes I go to the local libary and try locate local battle grounds. Try stay away from forest area, its pretty hard to dig there, because of the roots, and you have to dig deeper to get the older stuff. Very shitty when you dig deep and only find some nails from the 1970s.... Think around old railroads is your best place in America (because workers), maybe try locate battle events close to your area. Maybe a caravan route would also be exciting. Sorry for my terrible English