I will be following it's progress closely and contributing what I can.
You may find that once you're out of school, your first job may not be primarily doing software implementation for precisely the reason you cited - lack of experience. Implementation should not be confused with mere programming - the former is part of a well-planned and executed software engineering process, and the latter is just ... well, not. Your first job may actually be in quality assurance (QA), where you would be tasked with conducting testing of your organization's software/hardware. You can help perform the same function with the X software and, while you may not comprehend how the code works (at least in detail), you should be able to understand how the software is supposed to work at a higher level of functionality.
Most large, long-term software projects, such as the X window components, include some sort of test suite of varying sophistication (BTW, X window is singular, not plural, there's no dash, and the first "w" is lowercase). The testing regime may be automated, usually using scripts written to run in a shell, Python, Tcl/Tk, etc., and/or may include manual operations that must be executed in very specific ways. That way, the software can be tested in a highly predictable, organized way with expected results completely documented.
You may want to see what's available for testing the X components and become familiar with them. Understanding the testing scripts and procedures should be easier than trying to figure out the X implementation at a lower level right off the bat. You can even practice on an existing implementation for another platform (e.g., an X server package for an x86 Linux, Windows, or Mac) to get the hang of how the tests are designed, set up, executed, and results analyzed. If it turns out that there is no rigorous test regime for the X components being built for the Pi, you could make a very important contribution by porting the test suite from another Linux platform to the Pi - if they're written in a standard shell or a scripting language, especially Python, the port should be fairly straightforward.
In any case, enjoy exploring your Pi - there is a heck of a lot in, or available for, every one of the OS flavors, not the least of which are multiple X server implementations.