You'd do well to learn the difference between integers (type: int) and functions before trying to go any further.
If you don't know any C, you're headed for a world of pain. I'd suggest you put aside your attempts at Objective C and Cocoa and learn the fundamentals. Start here:
1
Learn C on a Mac
Then move on to
2
Programming in Objective C
Then start working through
3.
Cocoa Programming for Mac
I made the mistake of starting with 3, realised I needed to read 2 by about Chapter 5, then about a third of the way through 2 realised I needed 1.
Do it the right way round and save yourself both time and a lot of headaches. 😉