You can use two differnt methods to order your layers.
#1 - From the layers sidebar.
Click the layers sidebar, you can drag each layer up and down to position the layer.
Check/uncheck the eye button to hide the layer from view.
Check/uncheck the lock button to lock or unlock the layer (when activated the layer box will have a red border to symbolize it is locked)
Use the X button to delete the layer.
#2 - Using the layer stack controls: