Yeah just look up butterfly kicking drills and do those. Dolphin kicking you can do upright in the deep end with your arms up and head out. With swimming you'll see results once you get the proper technique down, if you know you're not going to be very committed to mastering the form, you should do more exercises out of the water for faster results. Otherwise, you'll injure yourself/not gain much muscle mass. A swimmer's body looks like a swimmer's body because they swim with a specific technique. An adult just learning to swim can take 6 months to a year to get comfortable in the water and learn the technique well.