Hi Mike, and welcome to the forum.
Without going into a long treatise on your work, I'd suggest that you begin to do some critique work yourself. Look at the images that you've made so far, and when you get to one you like, ask yourself 'why' you like it. What is it about this image that works for you? Do you think you could improve it? How? Stand back (mentally) a bit and imagine that you're looking at this image for the first time. What are the main elements of this image? Where does your eye go first? Where do you go (visually) from there? Does the image capture and hold your attention or does the eye go wandering out of the frame? Are there distracting or competing elements that draw you away from the main elements of the image? Go with your gut. Compliment yourself on an image that brings you a deep emotional response, something that captured just what you were looking for. Be ruthless with the rest.
There are many 'rules' of composition, and they can be used to effect but sometimes they can be creatively broken. The difference is knowing when and how, and this comes with practice. Fortunately, with digital you don't have to blow thousands of dollars on film for this exercise like some of us did in the past.