I was pretty shy about using my detector at first too, Ive never really hunted my own yard yet(house built in 50's) I went straight out to a park(hunted some trails in the woods), if it doesnt say anything on a sign about it I figure it is ok to hunt it. I live in a large city so Im pretty bold about most things and the detector is no different now. If I see some construction going on downtown I park and get right on it though there is always a pile of trash to contend with Ive never hunted anywhere and not found something ,almost always at least a couple pennys. Schools are by far the best place to start out detecting I think. The woodchips make for some easy digging so you dont get all wore out digging up pulltabs and you will learn what different coins sound like when they sound off. Ive had a lot of luck around high schools too,as a rule wherever there is a bunch of kids there is a bunch of money and other things under their feet.A really good spot to look is at the entrance to the football stadium if there is any grassy area near the gate its a cant miss for coins. If you still arent ready to leave the yard dig a few holes of varying depths and put different coins in them,see what each sounds like and har far down your machine will go,its also a good time to mess with the discriminate and sensitivity,see what seetings you can pick things up at and when you can no longer hear them.
Once you get some headphones you will really feel like you know what you are doing,even if you dont you will at least look like it and you will be saving tons on battery life,you cant imagine how much that little speaker eats up the batteries. Ive got some Koss headphones,they were 10 bucks at Meijer,the real lightweight ones with the foam against the ears(though Ive lost one of my foam caps) they have worked great for the 4 or 5 months Ive been doing it. Once you find something good you will be hooked, two of my boys were hunting with me like the second or third time they were out using one of my extra detectors and they dug up a sterling ring with a nice little stone that the wife said she thought was amethyst,now they are hooked have to go with me all the time their interest wanes when we are in a slow area but they are always ready to go the next time.
As far as being a little old lady I wouldnt worry about that a bit. I was in Myrtle Beach in June and there was this little old lady who worked the dry sand as far as I could see in either direction every day that I was there(6 nights),she was a really good detector and I learned a lot just watching her from my balcony. I would try and hunt safe areas where you arent likely to get your detector or anything else you may have stolen by some thugs. Unless you pack some heat :}