proper serving etiquette?!

I just started a new job yesterday and part of it entails serving. My supervisor explained that I needed to ask each guest individually what they wanted - but nothing else. I just asked one person what they wanted, then plated their food and brought it to them, and then went to another person and repeated the process. and so on. I'm not sure whether that was the proper way and I wasn't able to watch my supervisor. I didn't like leaving the others unattended like that tho - it didnt feel right.

So - is there a proper way to serve? do I just serve each person individually (ask what they want, make it, then serve, and move on to the next person and do the same), or do I serve more than one person at a time (I'm nervous about this because I think I'd forget what they said just that fast).