Different mosses need different conditions, without becoming a moss expert it is best to find moss to use which is growing in the sort of place you want it to grow. Not all mosses like it really damp for example, and if you look you will see that many grow in quite dry places and that they are quite different from the mosses which grow in marshes. The shred it and mix with yogurt as recommended by Cast1es really does work well.

I read sometime back that a gardener , wanting moss in their area , put some moss in a food processor along with yogurt , then spread the paste where they wanted to grow the moss .

Shade. But I'm sure you know that.

I brought some from NC last October. I keep them inside a glass dome (glass tupperware upside down to be exact - yes, redneck glass dome). They are happy and healthy. I want to build a small water fountain and place the moss over rocks, while keeping a water flow beneath it. Maybe you should have some sort of constant water flow to it? Classrooms seem to be on the dry side.
I will take some pictures of mine tomorrow. They are also on indirect sunlight (under my carport)

Lol, I fertilized lawns for years and it was considered a weed, so I killed it.Maybe a terrarium type atmosphere would work.