Welcome to The Photo Forum.
The background colors are vibrant and your subjects have beautiful smiles.
Your full-length shot (the vertical orientation image on the right) is just a little tight on the crop. You've nipped off the toe of the subject on the right and left very little room for framing. The subject on our left has a pleasant pose with one leg in front of the other and a slight angle to her shoulders (I would have preferred just a bit more). The subject on our right is "square" to the camera -- which is not a flattering pose. Turn her body slightly inward and have her put her weight on one leg and let the other leg relax.
I love the smiles on the left (landscape orientation) photo, although you've done a bit of a "bullseye" with centering. Avoid centering the heads when composing your frame and move the camera down a bit. I this "half shot" (half the body) go for the the waist up (lower your camera) so that their heads are in the upper-third of the frame rather than on the veritcal center.
Exposure-wise, while your background is vibrant, your subject lighting is a little dull. A boost to lighting would help here.
Thanks for posting! Keep at it!