New World Mod Confusion

Ok, perhaps I am but a dumb thing so can I please have someone:

1. Dumb down how the Custom NNPC thing. (Like how it works, what not to do, and just general information.)

2. Explain to me if I can (and how i would) put the same NNPC's sprites from DOLPlus (i use goose+mysterious).

3. If I can't do(or you want to recommend to me😚) #2 then what one do you use for the NNPC sprites if there are more and ofc pls tell me how. (Im new to the game.)

Side Note: Is this the right flair?