I was sure that most classes don't let you start until 6 months. But if I am wrong and if they can accept your song at this age, then should be fun provided that your son is not allergic to chlorine...Have you asked your doctor about swimming classes?
I have been working at hoom for neraly 4 months and I am satisfied with the experience. You need to develop a daily routine and you need to be very very disciplined. It always helped for me to imagine my boss sitting behind me. And make sure to never work in the kitchen, lol!