Where can I learn about networking? - Sopuli

I tried to study a bit from beej.us [https://beej.us/guide/bgnet/] and I appreciated the style of teaching, but ultimately thought it wasn’t for me as it didn’t go much into depth and focused more on creating C programs. Is there some source where I can learn in a comprehensive yet easy to understand manner the fundamentals of computer networking, at least to the extent that is relevant for selfhosting?