The third and fourth are my winners. The lighting is very even and I like the amount of contrast you have. Very flattering for the subjects. To my eye there's nothing to criticize. Good work!
The second one is appealing and has potential to be great. I like the contrast and shadow on her face, but I think I want her turned a bit to her right so we can see both eyes. Or maybe a bit more to her left for a straight profile.
The first one is my least favorite but I can't precisely tell you why. I think it's partly framing and partly her expression. Lighting seems fine, though.
Anyway, I think the results are great for just starting out with lighting. You seem to be playing with different ways of using it, which is good. I own zero off-camera lighting and my brief forays with other people's equipment didn't turn out nearly as well as what you have posted.