Nearly every adult who tells me they cannot dance can name the moment. A teacher, a sibling, a PE lesson, a school production they were not put in.
It is a remarkably consistent story and it has kept a lot of people out of rooms they would have loved.
What is actually being asked of you
Learning a sequence and executing it roughly in time. That is a skill, it responds to practice like every other skill, and being bad at it at the start is the ordinary condition of learning a skill.
The idea that dancing is a fixed trait you either have or do not is the single most durable piece of nonsense in the whole field.
The specific fear
Not falling over. Being watched being bad at something in front of people who are good at it.
Let me say it plainly: everybody else is looking at the front and at their own feet. The mirror is there for you, not for them. In nine years I have never had somebody go home from a dance class thinking about a stranger’s timing.
Why it is better exercise than it looks
Coordination, memory and rhythm under load, which almost nothing else in a gym asks for. Learning a sequence and then performing it is cognitively demanding in a way that keeps working long after the cardiovascular part has stopped being novel.
It is also the only thing on most timetables where you might laugh out loud.
Which to start with
Whichever runs at a time you will actually attend, which is a much better selection criterion than style.
If you are choosing between something fitness-shaped and something technical, the technical one is usually the better first experience for a nervous adult, because there is more explicit instruction and less assumed knowledge.
The first class
Stand where you can see. Not the front, not the back corner. Expect to be half a beat behind for the whole hour and understand that this is what the first class is.
Go back. The second one is a completely different experience, and almost nobody who goes twice stops at two.