But you know C++, correct? I wouldn't know where to start.
I wasn't born knowing C++. I learn't it.
Hence the place to start would be learning it.
In order to work on scripts stuff you only really need to know C, then if you pick up a very high level view of C++ classes you can do pretty much anything that scripts can do.
And to frank for learning C there is only one book:
The C Programming Language, Second Edition
by Brian W. Kernighan and Dennis M. Ritchie.
Prentice Hall, Inc.
ISBN 0-13-110362-8 (paperback), 0-13-110370-9 (hardback).
A lot of people I know simply call this book: "The Bible"
If there is a better book on the planet for learning C, I am not aware of it.