I think 16 is a good age
I would venture maybe 7th grade as long as it was well chaperoned.
I think 7th grade is a good age to start going to dances at school and at church.
These days, sixth graders are having school dances. I've never been asked to a dance, since I'm homeschooled, but I've taken dancing classes and have done plays where I have to dance with a partner.
I had my first school dance in sixth grade. They just taught us the box waltz then on fast songs we danced however we wanted. They just gave us little cards with about 12 lines on it so we could sign up with partners and we couldn't dance with the same person twice. It was actually a lot of fun!!