Hello Ben,
There is a lot to grasp when you are just getting started. The best way to learn would be to go through the documentation first, then attempt to modify and manipulate the code.
You can reference this post and follow the links to the documentation. http://e2e.ti.com/support/low_power_rf/f/538/p/259987/909317.aspx#909317
Familiarizing yourself with the BLE nomenclature will also speed up your understanding of the code. Download the Core Bluetooth specs and the examples/tutorials that are available.