In American style Waltz, normally the man's first step of the basic (left) box is moving his LEFT (sorry, I wrote "right" previously and missed it when I proofread what I wrote) foot forward. The man continues dancing the box during a Natural Underarm Turn; he raises his left arm to lead the turn on the "back half" of the box, which begins when he steps back on his right foot. (This isn't just arbitrary; there is a good reason for it.)

As another poster has pointed out, the steps are only a small part of dancing--though that doesn't mean that the foot positions are unimportant. You need to learn them, but you will be better off not concentrating too hard on them. Practice enough so you don't have to think hard about which foot moves next and where it goes. You don't do it all with your feet. You really want to think of moving your "center." When you walk you don't stick out your foot and fall on it (unless your name is Charlie Chaplin). When you dance, you don't do that, either.

A former (because he retired) instructor put it very well: "The body places the feet. Your feet just keep the rhythm." That will mean more to you as you progress. I hope you continue to enjoy dancing.