Q.Planting Creeping Thyme in Denver
I’d like to plant Creeping Thyme in between stones in our backyard. The stones are on top of sand. Is this ok? Do I plant seeds and will I need to water?

Creeping thyme should do well in between the stones. I myself just planted creeping thyme in a similar manner.
I have a small layer of sand over the soil to lock the stones. I started mine from plants but you can start seeds and then transplant them to you garden.
Here is an article with proper care and growing conditions.
https://www.gardeningknowhow.com/edible/herbs/thyme/growing-creeping-thyme.htm