On the photo of the girls, look at the closest girl on the right. Eyes are bright and clear with a hint of the colour and no distracting shadows on the face. That is perfect. The problem is that the same is not true for the other girls. When taking photos outside, watch for the problems created by shadows.
Some possibilities are change location, use flash to fill in the shadows, or use a reflector to direct light to fill the shadows.
In the beach shot, you got great texture in the foreground. The sun is overexposed and somewhat shapeless which is understandable but still a visual problem. A small aperture such as f22 or a neutral density filter might help solve this problem.
skieur