Tom, where do I find the laws, codes, rules, ect.?
matrix1272, good question. Start by:
a) going to the entities website (if they have one). Nowadays, it's getting to where most cities of any size, and most counties, have their own websites. The laws, charter, muni-codes, and so forth, might be on there as a clickable link. There might be even a key-word search function. If so, that makes it easy. Key words of various combinations like "metal detectors" or "detecting", etc...
But admittedly some places either don't have websites. Or have websites that don't go into detail on anything that deep. So in that case:
b) See if it's not at city hall, like on the front counter, in binder form. Or perhaps at the city library. It's got to be
SOMEWERE for public viewing, lest .... how else would anyone be able to know the laws?

You can even ask around at city hall where this info. is. And hey, in that way, you'd be satisfying your urge to go "talk to someone" at the same time

You'd ask: "
Hi, where can I find the listing of city laws, codes, the charter, etc...?" And perhaps they'll direct you to where it's located in book form, or provide a weblink for you, etc... It's simply got to be SOMEWHERE, as .... nothing like that is "secret". Laws and rules are not "hidden" or impossible to find.
But quite frankly, to be honest with you, give a little thought to what squiggy1 is saying. Because to be honest with you, something saying "no metal detecting" is rarely on books at city or county levels. But .... sure .... in the interest of being a "family forum", you can go an even higher road, and look things up if you're skittish. But honestly, I go to any town I come to, and hit any park that looks good, ... in the absence of a sign. Could I go "a step further" and go look down at city hall, in addition to looking for signs? Sure! But just saying that 99.9% of the time, you'll also find nothing at most city and county levels (it's nearly always silent on the issue). At least in CA (if that could be used as an example), I can think of perhaps a single city out of HUNDREDS that ever had such verbage. And two counties out of 58 counties that has any sort of "permit" (and oddly, no one ever cards you in those counties, nor does desk clerks even know what you're talking about if you come in asking to get one).
A word of caution: Just because there may not be a rule saying "no metal detecting", does NOT mean that therefore, you can go nilly willy waltzing over people's beach blankets at arhaeologists conventions at historic monuments. I mean .... c'mon, a little ... uh ... "discretion" is called for here. ANYONE can gripe at ANY time. Let's face it, we're in an odd hobby that draws curious on-lookers, and has connotations. The same can be said even if you followed people's advice to "go to city hall and ask 'can I?'" questions. People have done that, gotten a "yes", and STILL run into busy-bodies who think they'll leave a mess, or whatever. When the gleeful md'r whips out his permission, guess what happens when the gardener or cop gets on his cellphone, calls to city hall, and says .... "
but he's tearing the place up!" ? (which isn't true, but that won't matter). Your permission is promptly revoked. So matter HOW you slice it "permission" or "just go", we STILL all need to use a little common sense. Avoid obvious historic monuments, don't be in the middle of retrievals when busy-bodies are watching, go at off-times, like before 8am, or after 5pm, etc....