I'll be entirely honest and transparent with you, at this stage in development, Atticus is not ideal for low content books like yours, however it is possible to create them.
The easiest solution is to import a jpg or png file and use it to create a Master Page. Once you import your image and get the formatting and layout perfected once, you can turn it into a Master Page and use that to Add a new 'chapter', as we call it, but in your case it would simply be a new page. You would just need to repeat this for as many pages as you'd like in your book. You can also create a variety of master pages, and add them as necessary.
I would recommend you size your images for the proper trim size for your book. You can either:
size your image for Trim Size minus Margins, and then insert the image at 100% and centered within your page. This will allow for Atticus to apply the appropriate headers.
If you want the image, such as lines or graph paper for example, to be only part of the page, you’ll need to preformat to fit the width of your book, minus margins, and only as high as you would like it to come on the page. For example, a 6 x 9 book might use a 5.5 x 5.5 graphic, with room for text at the top of each page.
size your images to be the trim size including bleed and insert it as a full page image instead, but this option won't have any headers/footers and often the page numbering is quite useful for low content books, but the option is there!
You can learn more about sizing images for different trim sizes in this tutorial: https://www.atticus.io/calculate-image-size-for-print-and-ebooks/