You are clearly learning how to isolate part of an image by using the aperture/depth of field, which is a good thing.
However, I think you need to give more thought to how you use that creatively. You should also pay attention to how you frame your shots.
Shot one - the sole of the shoe that is in focus has been cut off at the bottom which feels messy/unsatisfying.
Shot two - you have a large out of focus bag sticking into shot in front of your subject, which is distracting. This would look better if you moved the camera fractionally to your left so that there is less of this bag showing.
Shot three - basically the same problem. You have a big shoe at the front of your shot that is out of focus. Because there is so much of it in shot it is distracting. In addition the shoe you are focusing on is hidden away in a jumble of other shoes and isn't clearly visible.