I am a lifelong swimmer who (this fall) got a membership to a new local pool so I could swim laps.
If you are brand new, you could take one lesson and have someone give you tips on how to improve your strokes and then just practice, cause that's really all it is. Get the mechanics down and go
Or find a swimmer friend who could assist. The ubiquitous YouTube videos probably have something to offer too.
I do crawl (freestyle), breast stroke, side stroke and back stroke. 2 laps each, then repeat. I think back in the day that was referred to as individual medley (but the side stroke was butterfly, which I can't do anymore). It's a nice mix and my one hour passes pretty quickly.
I've been going since October about 3 times a week and see a difference in my body shape.