Writing Code in the Application Xcode

Hey, I'm pretty new at this. So, 开发者_高级运维I just downloaded Xcode from developer.apple.com and I'm currently getting to know the application. Getting to the point, my question is, where do you type the code?

Double click on main.m (or .c or .cpp) or open the file into new window.
XCode has usually split windows. The upper side for the files, the lower side for editing. But this is depending on how you setup XCode.