That's some flat lighting, to say the least. The light lacks dimension and mood. There's no lighting here to set the photographs apart from snapshots. When posing a female, it's generally not a good idea to put her body square to the camera. You want to create angles and curves to accentuate the form. What you should do is study portraits you like to see how they're lit and what the light does to enhance the photo. Don't think of it as looking for stuff to copy. Just study the techniques and learn how light enhances photographs. Research classic portraiture and understand the fundamentals.
Master backgrounds. For example, in 1 and 3 the background is distracting and in 3 there's a white stone jutting into the frame. Eliminate distractions in camera. In 1 the reeds and trees are distracting. If something doesn't add to the picture, it will distract.
But I can see the thought that went into the pictures and if you keep learning and trying to improve, you will.