Hi @jesica438, welcome to the Supernotes Community!
Tags are best used for categories notecards across different parents or for quickly filtering and refining lots of cards within a parent. I often tag my cards by location, or characteristics. e.g. I have a “Restaurants” parent card and a “Recipes” parent card. Some of my restaurants and recipes child cards share tags such as “Japanese”, “Italian” or “Pasta”.
You might find the following topic useful discussing the comparison between parents and tags:
Also @freisatz wrote up some excellent notecards on how to use tags, parents and more. We’ve been meaning to publish this as a community resource since we think it’s presented and very well thought through. If you have any specific questions let us know and we’ll be happy to help 