@AnnaKelly ...

Design Tools (DesignPLUS) is a paid third-party product from Cidi Labs.  You can use that tool to design page templates and designs for page banners, headings, and a wide variety of other things.  These templates can be brought into course pages so that you have a consistent look and feel to your courses.  You can read more about this at: DesignPLUS for Canvas | Cidi Labs.

Since you only have a free account, one idea for you would be to design a module with some pre-built template pages that you made.  Then, you could make copies of these pages to re-use throughout the course...and just fill in the missing parts (such as if you had a different title for each of your banners at the top of your pages).

Other folks might have some other ideas for you.  Good luck!