These are great photographs. There is no need to doubt yourself if your work isn’t meeting your expectations yet. The important thing to consider at this point is the technical elements to your photographs. It’s important that you do more than point your camera and “click”. Understanding the theory behind composition and the technical elements of framing an image (including depth of field and shutter speed control) are very important parts of the photographic process (as is lighting, understanding shadows, lines, shapes, color theory etc). Slowly, these things will come naturally to you and you’ll be able to focus almost exclusively on visual story telling. However, at this point, understanding these technical attributes is critical. It’s a necessary first part of your journey.
The technical elements in both photographs is exactly what we were looking for. Your first image completely isolates your foreground from your background. You’ve used quite a shallow depth of field for this image so the background has become textured negative space made up of gradients of purples and greens.
However, from a composition standpoint the image is not quite centered, but also doesn’t abide by the rule of thirds. It would have been nice to see you experiment a little with object placement in this photograph. That being said, the color palette and color control is fantastic. It’s a very strong image.
Again, your second image accomplishes the technical feature of stopping time. Fireworks are constantly moving (and quite hard to capture because of the dark nature of their outdoor environments), but you’ve managed to freeze the fireball in the air. Great work.
My main concern with this image is that it seems to me that the subject and composition are giving themselves to the visual idea of symmetry. The circular firework is seen in the middle of the composition spanning outwards. This is against the rule of thirds, but the symmetry becomes a stylistic approach to the composition so it seems intentional and interesting. I really like this. My concern is that if you’re going for symmetry, you must go all of the way, or it looks a bit accidental and awkward. Notice that you have more space on the right side of the frame than the left? You’ve cut the firework off a little with the left frame while there is still space on the right side? Obviously fireworks are unpredictable and impossible to control (which is why firework photography can be so challenging). However, paying attention to these small spacial details will make you a much better photographer in the future.
Overall, great work!