My coworkers and my supervisor. The work was also very rewarding when the kids made progress.
What I wish was different
I wish I hadn't worked Saturdays; only having one day off at a time per week made the summer less flexible so I stayed home most of the time unless I had someone cover my Saturday shift.
Listen to your more experienced coteachers, but mostly observe and adopt procedures they use. But mostly have faith in the process; you will learn how to teach kids to swim, you will get the hang of it before you know it.