Some sites lack coins. Rare but it happens.Some people did not carry money much and some had little to lose. But keep access to where you hunt now if you can to revisit when your more comfortable with coins. Nail heads are stimulating as are bent nails, they are round and a type of metal,should the detector say something or ignore it? I,ll take let me know as it is trying to help me find a round metal object.You have lots of nails.Most were likely part of a structure there that collapsed. Where are coins that were there before the nails and how can you reach them through a layer of iron? Take a coin and nail and experiment with what you can tell with nail on top of,along side of ect.. Your location not mine so soil conditions likely differ but I start out usually in jewelry mode and two bars knocked off the sensitivity(if in doubt go a notch lower) and iron discriminated up to foil. Most iron is a low tone but you will find foolers on some nails and other items. All ways check after a recovery as scores have come after removing iron that blocked/stepped on a coin. Plant a test garden with likely targets that,s labeled or a piece of cardboard or a rug with objects secured to backside to practice. At least toss a coin close and test on it though long buried can ring up better. Try a public park maybe and dig some newer stuff. Its learning the detector is all.High tones get my attention. Swinging tight on them to get a narrow target is great chance. stuff running up and down or back and forth,is usually not the greatest but one way to be sure. Lowest tone is ..well you know unless you want iron. A ding ding ding high tone when coil is barely swung like the target is narrow is often the winner in coins. A two inch same tones often a bottle cap but to be sure dig them till you can call one before you dig.(I still dig a few,they sound so good when hunting is slow l.o.l.)So if your on a site wondering, drop a cent where you can see it and swing over it for that ding ding ding to test. Iron can distract you and your detector. If you think a coin is in there keep cleaning out the iron. To often when I am pinpointing I get suckered into the stronger iron and it can put me digging something two or three inches away from a coin because the iron is yelling hey over here!With the settings I start with iron gets nulled a bit BUT and this is important to not miss areas, if icon stays lit up while iron is being nulled the detector is not reading anything else till it goes out. Keep at it and holler if different sites don,t produce coins,if that,s what your after. H.H.
Just keep digging you'll find older things/coins soon enough... 
