Hi, Priscilla. Just knocking on doors and asking the land owner has always worked for me. I tell them what I want to do and give them a description of why I want to do it (hobby) and what I'm looking for (coins, relics, etc.), promising that I won't harm their property in any way. I show them how I retrieve items, etc. and promise not to leave any large holes unfilled and that I will remove all trash that I find. Your approach needs to take into account whether you want to hunt their yard or, in my case, usually fields where they plant crops each year. I know this sounds too simple but it has worked for me for many years and seldom have I been turned down. Just be aware that some people will be naturally suspicious and you will get turned down sometimes but you will be surprised how often people become interested in what you're doing and are curious about what you might find. As far as schools go, I haven't hunted on one in many years so I don't know about any laws that affect that now. I used to just go into the school office and ask who I needed permission from. I told them, as stated above, what I wanted to do and that I wanted to do it after school hours or on weekends. Never got turned down very often, and while we're on this subject, don't forget old church grounds but if they have cemeteries promise to stay away from those. There are numerous possibilities for sites to hunt. You just have to not be bashful and go right up and ask. And if you can get them to give you a written slip showing permission it's always a good idea but if they balk at that don't press it. Just take their verbal permission and go for it. Also, just because someone gives you permission once doesn't mean you have permission to come back unless that is arranged beforehand. Now, get out there and do it. Best of luck to you.
Jerry