twilli1, when you say you are "not finding anything", is that to mean that .... litterally ....... you are "not finding
anything"? I mean, not even tabs, bottle caps, foil, nails, or .... SOMETHING? Or do you mean "nothing OLD"? (or valuable, etc...). Please be specific.
My advice to you is, to hook up with someone in your area who is finding stuff. Like if you meant any coins at all (like for clad/jewelry hunters), then simply hook up with someone in your area who is finding stuff like that, and see how they do it. See what type places they hunt. See how they avoid busy-bodies like the type you ran into (perhaps you were sticking out like a sore thumb or something). If you meant old coins, then hook up with someone in your area who routinely finds old coins. See how they do it, what type places they hunt, what type signals they're looking for, what type signals they pass, and so forth.
Because yes, I can only imagine, having been hunting in my city for 35+ yrs, that I too would pity the poor soul to picks up his very first metal detector, and goes to the "obvious spots" (the obvious oldest park, the obvious oldest fairground, the obvious stage stop with the marker right on the road-side, and so forth), and thinks he's just going to pull up 4-star banging easy seateds and barbers

But they're still out there. You're just at a disadvantage if you're new to this, because ..... it's true ..... if you're in a heavily hunted area, then the easy-pickens are usually gone.
But if you just meant clad, then there should be no shortage of places you can go and bulk up on that. And even if you meant jewelry, just go to any swimming beach, and dig enough low conductors (because jewelry too is constantly replenished).