You're right - you (and everyone when they start out) have to spend some time learning the basics. If you are not familiar with MIDI then you need to spend time with Google (not Line 6 documents) learning about MIDI commands. Once you have that understanding you can apply the Line 6 docs when using the Line 6 devices to send and receive MIDI commands. The Line 6 docs are, understandably, focused on applying technologies like MIDI using their products under the assumption that the basics of MIDI are already understood. They are not MIDI-For-Learners documents, nor should they be.
Similarly, there are many chorus, flanger, and phaser pedals in the guitar pedal history. Each of those pedal types have different effects on tonality, and there are many examples of each type. Within each type, the pedals tend to have similar controls. The specific pedals modeled by Line 6 will have the same controls as the originals - but the Line 6 documents may not be helpful in explaining the controls in temrs of tonality. You need to spend some time with your friend Google again to understand what that product is and does, and what its controls do in terms of tonality.
Sorry, but there's really no short cut. You need to do some research, gain further understanding, and then experiment. In this case, there's much to be said for learning by doing.