Where should i start to learn about ethereum at its ecosystem

I recently started to learn about ethereum. Oh boy! I was so confused about everything. I like to understand things from the basics like how private and public keys are related, how a digital signature is verified and so on. I kinda have a fair idea of how bitcoin works but I am not able to fully understand ethereum and its ecosystem. Can you suggest some sources from where I learn about ethereum that can explain to its core without being very technical ( a little bit technical stuff is fine ).

EDIT : you can also suggest some discord servers or subreddit.