This might get to you too late to help, but I want to chime in with the other excellent comments above and say "Way to Go" in sharing your time and knowledge. I have a couple of personal thoughts based on enjoying the heck out of public outreach for almost 25 years.
The best observation I ever heard about doing outreach has really stuck with me for over a decade. "You never know what life you'll touch, or might touch you." What I get back from the visitors is a tremendous feeling of well being, having helped broaden their environmental awareness and introduced them to their home universe. Some of my younger visitors over the decades have gone home and started science clubs at their schools, and even become science teachers. I've done some sessions for families of kids with cancer, who, because of one night under the stars, felt a connection to something bigger than themselves. And I've participated in some events at a drug rehabilitation facility and learned to tell some life-affirming stories about constellations and asterisms, which seemed to bring a bit of peace to the participants.
Introduce them to your time machine, because most of what they'll see happened quite a while ago. As much as you try to prevent it, don't freak out too much when an eyepiece is grabbed. It WILL happen. Humans want to bring information or food TO their head. Just keep repeating every half dozen visitors to your scope, "Look with your eyes, not with your hands."
If you do have a smart phone app than can provide answers, great; saying you don't know is fine, and tell them you'll have to check it. Maybe even tell them they now have homework and challenge them to also look it up for themselves at home.
Most of all, have fun with it. Maybe, like mine, your life will be the one that's touched by the experience.