Welcome to the TreasureNet. Please tells where you live and what kind of environment you will be hunting in. Like parks, fields, beach etc. We will then be better equipped to make suggestions. Good luck!
1st - I noticed this was your very first post - so, Welcome Aboard! Take a look at Forum: Illinois for information (i.e., clubs, etc.) directly related to your state.
2nd - I moved ya from HELP! over to NEW MEMBER INTRODUCTIONS for more exposure.
Define “best”...if you are a new operator and are looking for success in finding old coins right away, PRIVATE property in old sections of a city will be your best shot. Any “good areas” of public land have been hunted for the last 45 years by everyone else, and as you go, you’ll realize what you’re up against. Old coins are out there...somewhere. You have to be one very wily coyote to find them. Watching posts of people finding old coins all the time will lead you to believe it is easy. It is not. Just a reality check....good luck.
I agree with old house permissions, however, you need to go to the parks and schools for hours and hours and hours to learn the machine and what it's telling you.
Going to an old place to find old coins without knowing what you're doing might lead you to simply swinging right over the goodies and not knowing any better to dig.