To begin with start with a brand new file in Photoshop, you can do this by selecting File and then New. Upload the image you ...
In a similar manner, add multiple layers that you want in your output GIF. If you want to import some transparent images to your GIF animation, you can do so using the File > Open as Layers option.
When putting together graphic designs or editing photos, opaque backgrounds on images can be a hindrance - so knowing how to make the background transparent in Photoshop is a useful trick.