You could try this tutorial: https://www.google.com/amp/s/www.lifestorage.com/blog/diy/diy-kitchen-shelves/amp/
Here are lots of ideas from here on Hometalk: https://www.hometalk.com/search/posts?filter=build%20shelves
Have an idea of your measurements you want to finish with and head over to your local home repair store. There is usually a section for DYI shelves and guides as far as spacing for support brackets.
check this out: https://www.hometalk.com/29499465/how-to-build-easy-farmhouse-shelves