My little one doesn't know how to swim and during our last trip to Fiji, he has learnt how to kick and float on his own. We bought him the safety ring and he just started to float, kick and spin comfortably after a few days of learning.
Once he got more confidence, he was able to glide and kick off the wall which was a huge improvement from when he first started.
I find you learn better when you were young and aren't afraid to make mistakes. You learn more with mistakes and remind yourself don't do them again next time.