If you're new to iOS or OSX development, then Xcode may be somewhat of a mystery to you.
Luckily there are lots and lots resources available to you. Including NSHipster and objc.io and a range of free iBooks from Apple, such as "The Swift Programming Language" and "Using Swift with Cocoa and Ojbective-C"
Apart from having to get Xcode, learn the quirks of the IDE, the languages and then tackle the mamoth frameworks of Cocoa Touch (iOS) and Cocoa (OSX) — there's also the matter of code style. A quick Google search will lead to a range of links that are worth having a look at.
- Zen and the Art of the Objective-C Craftsmanship
- Google Objective-C Style Guide
- Ray Wenderlich
- The New York Times - Objective-C Style Guide
- The WebKit Style Guide
I'll let you explore those at your leisure — but as a quick start may I suggest to you Alcatraz. It's a package manager that lets you install Xcode plugins (yes it has plugins), themes and templates. Once you have that installed, install the ClangFormat plugin and choose a code style that suites you — or create a custom one that suites you.
Of course, there are lots of other good plugins worth getting but start with this one and set your code out on a readable path.
Which brings us back to XKCD.