What coding language to learn to make CS:S Hacks?

I am new to coding and I was wondering what language to learn to make hacks for mostly CS:S. I have heard C++ & Java are some to learn. I can learn Java that seems easy but C++ is more useful. So here is the main questions:

1. What language do I learn?
2. Where do I learn it? Site or Book?

The best language to make a gamehack is c++, u can seach around on youtube for TUTs.