Adding thumbnails for subpages to pages

Hello. My site is https://www.openbluewindow.com and I have made a page called “i like” which basically is meant for me to post all of the things i like (art, music, photography, etc.) I want to create subpages (i already have two)…but they only show up as links. I want to have a thumbnail or photo that you can click on that takes you to the subpages…rather than just having links. Please advise. Thanks!!

Ideally, I would like the thumbnails to run in a grid, similar to the site https://www.yayeveryday.com, but this may take some coding. I understand SOME coding, but i am not sure that i could pull this off.