Here is a multi-LED loop sketch I undertook for Becky’s Making Studio course. The more I stared at the code, the more it made sense, although at first, when I ran the sketch, it didn’t work. Turns out I had my pin legs oriented the wrong way; the current couldn’t flow the way I had them set up. Luckily, by back-tracking and running a single-LED sketch, I was able to see where the problem was!