Swimming is age-agnostic. As long as you have the desire to learn, you can start now.

Case in point: Our oldest student is close to 70 years young!

We suggest you first check with your doctor and seek professional medical advice on this matter. As far as we know, swimming can yield tremendous health benefits for some conditions, so check with your medical professional first before embarking.
Everyone learns at a different pace according to their own abilities. Try not to limit yourself to the number of lessons. Rather, get your basics right and build a solid foundation from there.