"Education is an important thing."
Translation:Edukado estas grava afero.
This sounds good to me. There are differences in how the article is used in Esperanto and how it's used in English. The tricky part is that this is a translation based course, and it's hard to know when to deviate form the example. The safe move, in the course anyway, is not to.
I recall PMEG says there isn't much difference between a sentence like this one with or without "la". I believe this is the relevant passage.