I can't be of much help; not a modder myself.

Some useful stuff is located in:

https://forums.totalwar.org/vb/forumdisplay.php?f=69

https://forums.totalwar.org/vb/showthread.php?t=30621

That forum probably has the the most useful stuff, but there are other resources located around the .org.

Good Luck and Welcome to the .org!