Lake Swimming

So I just want to start going swimming. There is a couple pools in my area but they are expensive and I want to take advantage of the summer weather and just get out there. I want to start just going swimming at lakes? There is a ton around me but I think I’m just worried I would be breaking some kind of rules or something? I tried to look at some of my local laws and I can’t find any, so what is stopping me from just going to the boat launch and going swimming a few laps? Like if I wear a bright reflecting cap I should be pretty safe if I stay away from high boat traffic areas and close to shore. But I don’t think I would be breaking any laws. Should I just start going for it? As long as I keep safety and abide by any posted laws and local ordinances? Don’t know if this is the right place for this or not. I just love (lap) swimming and haven’t went in so long.