New to coding stuff for realm

I am interested in creating programs and stuff for realm using a program language. I usually do onscreen stuff such as AHK, but I want to get more involved in clientless programs. I prefer to use C++ and am somewhat new to some of the commands. My question is where I can I learn how to talk to the realm servers using packets and stuff. How did you guys learn, youtube? Also, how can I intrepret the packets coming from the server. Say for instance the server sends information there is an enemy or bag near me. Im trying to learn how to do stuff such as kill the enemy or pick up the loot. I know auto aim already exists. What are some good reasources for learning to talk to a server?

realmrelay