Religion

My first thought to suggest was The Seven Storey Mountain. It's the very readable autobiography of the part of his life when he went from being a college student to a monk at the Trappist monastery where he spent nearly the rest of his life. That and New Seeds of Contemplation will get you a good start. They seem to be numbers one and two-or-three on the lists written by people who've read far more than me.

https://www.patheos.com/blogs/carlmccolman/2015/01/seven-essential-thomas-merton-books/

This page has selections from the books (like Google or Amazon samples), but it wouldn't load on my phone properly.
https://englewoodreview.org/thomas-merton-intro-reading-guide/

Edited to add one last link, to Merton's famous prayer (from Thoughts in Solitude), in both text and audio:
https://onbeing.org/blog/thomas-mertons-prayer-that-anyone-can-pray/