Fuck applescript. It's useless. Learn C++. Learn pointers, arrays, structures, functions, and classes. Make sure you learn procedural programming before before you learn OOP (object oriented programing). In other words, learn how to program well with classes first, and then learn how to use classes. You can find the best tutorials at
http://cprogramming.com/ and it'll be easy to find the shit I listed, it's all in a list. Learn the tutorials in order until you know everything I listed.
You'll also need a compiler to turn your code, which is basically text files with a .cpp extension, into a program. Here's a free one straight from apple for free
http://developer.apple.com/tools/mpw-tools/.