For the templates, there is a free template that will do a standard class size up to 40 images. You can add your own graphics to the template.
There is also a templates for larger groups up to 120 images which is 1/2 price at $15 when you log in. You can see them at this link.
These template layouts are very complex to make so I don’t recommend making you own. It’s much easier to just add your graphics to modify an existing template.
I have a layout designer I plan to release this winter that will help make layouts. However, right now, it is a manual process to make layouts and very complex as mentioned. So for now, assuming you are doing normal class sizes, just use the free standard class template and add your own graphics.