>>8684849 year lifeguard here. I've taught kids ranging from 5-12 years old and adults ranging from 20-40. Nobody cares how old you are, just go to a university and sign up for a swimming class. You'll be surrounded by so many moronic Chinese and Indian people that the instructor will love you just for being able to speak English.
You really should learn how to swim, it could save your life some day. The amount of effort it takes to learn enough to at least prevent yourself from dying is not that great. You don't need to become a pro swimmer, just learn how to elementary backstroke and yell for help.