Hi, you need to make a new fill layer:
1. From main menu choose Layer/New Fill layer/ Pattern
2. In the New Layer window, choose a name for your layer and clic on OK
3. In the Pattern fill window, choose the pattern you want from the menu of the preset, to move your pattern you just need to drag & drop the mouse directly on your woking window.
Once you make your new fill layer, you can change the parameters from the Layer Panel. Just double clic on the thumbnail and you'll access again to the Pattern Fill Window.
