There are a few things you can do to help find the center of your canvas in Photoshop. The first is to use the eyedropper tool to select a point on your canvas and then use the mouse wheel to move that point around. The second thing you can do is use the Marquee tool to select a part of your canvas and then use the mouse wheel to move that part around. Finally, you can use the Size tool to resize your canvas so that it’s just about right for your needs.