A few thoughts:
1: Is your subject the man or the door? As the door does not suggest a specific location, profession, situation in life, I feel that it is taking up too much of the frame and not improving the image at all. Given that I see nothing special in the door, I am guessing the man is the subject. If so, I know almost nothing about him. Did you just take a picture of some random guy leaving some random building, is he waiting for something, etc? All this image does is open questions without any hint of an answer.
The composition of the image is not great either. The man's head is almost perfectly centered in the frame like a bulls eye. Try using the lines/shades on the door to compliment the man. Currently, the light part of the man's jacket is on top of the white trim. This hurts the separation between the two. Going further from that, the contrast of the man is not bad, his white shirt is properly related to his black bow tie, but the large gray door makes the image bland.
2. The composition is much better than #1; I probably would have moved her head down a little, but not by much. I really like the different tones in her hair and how her face is brought forward by her dark dress and hair. The focus is right on her eyes where it should be. Overall not a bad image, maybe play with the contrast a little to get some lighter highlights, but be careful not to blow it out. It will be tough with her already very bright chest.
3. I think this is your strongest image in terms of composition. The wood adds a bit of texture to the image and breaks up the frame. Again, work on the contrast. The window in the back is the brightest thing in the frame. As a result, your eyes first go to that instead of the girl. The darkest blacks are also in the background which compresses the tonal range of the girl.
Overall, not a bad set of images for one of your first attempts. The things I would focus on are your contrast and composition. Make sure your subject is clearly defined and try to add some context to your images, otherwise you have nothing more than a snapshot of a random person, and in all honest, I don't have time to look at pictures of random people.