It’s worth learning something about XMOS technology, XC and the Xcore open source projects. If you don’t understand the syntax of the language, common XC idioms, and the code that already exists in the Xcore open source projects, it will be difficult to make a contribution. You don’t have to know every in-and-out of the language and the architecture, but the Xcore open source projects is probably not appropriate as the first place to write XC code.
Here’s some sources of information - there are also some tutorials built into the tools.
You’ll find more on the XMOS support website.