I don't know that anyone's much bothered by spoilers for that early in the game. There are some spoilers for much later in the game already in the previous comments. Anyway, TL is not the same thing as elemental affinity. TL is technique level: you need to get the level of the elemental technique up to at least 20 by fighting with it. And you also need to get the elemental affinity of that element up to at least 10. That's the part that might take a while at that point. But those are two different things. Once you have both of those things for an element, that element is ready. Now I don't remember exactly what it's ready for, but the techniques page should tell you. Anyway, that should get you pointed in the right direction at least.