To make a new layer without anything on it, go to Layers-> and select either Raster or Vector layer. A Raster layer has every feature available. The Vector layer doesn't allow you too use some tools.

To make an image a new layer, copy the image and then press ctrl+l to make it the new layer. Then you may alter it however you wish. When you do this, the layer will automatically be on top of the active layer. To change the active layer go to Layers and at the bottom it should show all the layers. Click on the one you want to be active.

When you use the the Draw, Text, and Preset Shapes tools there is an option that allows you to make them new layers, to access it go to the Tool Options box. If you do not have it click on the thing that looks like this: and the box should appear.

To name a layer, make it active and go to Layers->Properties and a screen should appear. At the top of the screen there should be a box with the word 'Name' right on the left of it. Type in the box what you want to name your layer and then press OK.