You mentioned in earlier posts you were looking at a US recipe. I think it's safe to assume the writer had Crisco
or some thing like it in mind. It's true that lard is traditional and shortening is the most common alternative but I recomend you use neither. Why would you want to use anything you think is "barbaricly unhealthly"? In the early 20th century Crisco was marketed as more civilized and healthy than lard but I doubt it's either one.
Luckily tortillas are quick and easy to experiment with. Try a 1/2 cup flour with a half tablespoon of whatever fat or oil you're comfortable with. Add a good pinch of salt. If baking powder is handy add a good pinch; if not, skip it. Stir in a couple tablespoons of water (just enough to form a dough).
I don't think you can learn to make tortillas by reading about them. It's nice if you have a friendly Mexican or Texican lady to show you how but mainly you have get your fingers in the dough (masa).
Let us know how it turned out.