Learning materials - Category Theory

any recommended books/pdfs?

7 Sketches in Compositionality :)

thanks, I'll check it out :)

I also recommend 7 Sketches in Compositionality as well as the category theory posts on Tai-Danae Bradley's blog, https://www.math3ma.com/

Her booklet on applied category theory is a good introduction to many concepts that will be further elaborated on 7 Sketches: https://arxiv.org/pdf/1809.05923.pdf