How old was your LO when you started swim lessons? Did they actually learn how to swim, or was it more just getting them used to the water?

C is 15 months. Thinking about starting some kind of swim lessons but honestly, don't want to pay for them if it's only about getting used to being in the water. The gym near us has family swim sessions for $10 a family where we can bring her to just play in the pool, which is cheaper and more convenient than lessons. But if it's a fun class where she will learn some and be entertained by the teacher, then I might ask for it for Christmas...