Getting started will be the tricky part. Once I get the first one, references will help grow, so that brings up another question. Should I offer a good discount for the first child in exchange for being a reference once they "try me out"?

the male provider made me uncomfortable. I think it was mostly this guy that made me nervous
That could be a good thing. No parent should leave their child with someone they feel uncomfortable around or nervous about, man or woman. Feelings can have good reason.

he also kissed her on the first visit
That right there says don't leave her there. Neither man nor woman should kiss a strangers child after a first meeting. I've had a few dozen different children in my life, but only 11 that I have ever kissed, and that was never until I knew that they knew I loved them, and it was also never on the lips either, or if I felt they didn't want a kiss. Same with hugs.

Sexual abuse is a topic all of its own, and something I plan to teach. My website and parents handbook say that I will be teaching about that topic, age appropriately, unless they say no. That's a serious topic to me.