Okay, so basically I got stuck making a magic system because I thought it wasn't "cool" enough and I started rewriting it from scratch. I instead added a few elements and an origin and kept most of the frame work (i.e. how it's used, its side effects, etc etc).
Basically, in this world you have these spirits called Triven. They can be mindless or basically gods. Each individual (or species, depending on whether they're mindless or not) has a specific set of powers or just a power. Three powerful Triven all, by chance, have the ability to create Words of Power. Very rare. The first, Almnei, is very methodical. He creates a rune system called Carn, which is neat, very nice in calligraphy. The second is Kindril, who was very playful and thought very quickly. Her script war called Nirid and was more flamboyant and rudimentary, written more with haste than with care. Nesrin thought mainly in abstracts and saw that her fellow Triven had created their scripts in two dimensions. Wanting to distinguish herself, she created her script of Kalni in three dimensions. The three Triven then imbued all the scripts with their power, allowing the different scripts to be used in the same phrases.
Carn is now mainly used when writing runes due to how neat and clear it is. Nirid is used when magicians make complex hand gestures in the shape of the strange runes. Kalni is sometimes used in complex hand gestures but is largely used in magical technology.
None of these have any spoken form that a human can make, so humans instead just assigned each rune a name. Like how Hiragana and Katakana have different symbols for the same sound, often the three magical scripts have three different runes for the same thing, though Kalni often has more strange, abstract meanings than the other two, which tend towards more concrete things.
So I'm wondering how I could have this magic system be introduced to the humans. My first thought was that the Triven made notes of their invention, which the humans later found, but I wasn't so sure of this. Maybe the Triven had followers, who learned their magics and passed them down through tradition?
I'm not sure. How could I do it? I want the story I have to be focused on the humans and what they do with the magic. I don't want to have the focus on those who invented it.
EDIT
To use magic, people have to do two things as well as be touching the rune: They have to be in physical contact with a grey metal called sangium They have an energy source that is the lifeblood of their soul called Sang. They have to consciously draw out this Sang in order to activate the rune.