This article shows you how to hide a layer when you don't want it in a specific format in the same template collection
If you want to hide a layer for good on your format then:
1. Click on the layer you want to hide
2. Go to the right menu and click on "build"
3. Scroll down and choose "Ignore in formats" and add a checkmark in the formats you want the layer to be hidden from.
Do you just want to hide a layer while working on other layers? See this article