This is kind of an average shot for me. The exposure looks ok, maybe a little too bright on the highlights, top left of main flower. Could you have used fill in flash to remove the harshness in the shadows, along the leaves?
Composition is kinda ok. I would say either walk in closer to the main plant and fill the frame or zoom out and capture the whole field. Try positioning the flower, further off centre at this zoom.
The DOF with F5.6 makes some of the front flower, soft. Why ISO 200? With ISO 100 you could have decreased the shutter speed and increased the aperature for a little more sharpness through the flower.
Try taking the picture from another position instead of "straight on". Try from above, or with such a large stem on the flower, from below. Also try F5.6 at a much closer distance, isolating one of the buds maybe?
With flora and fauna, filling the frame is usually the best approach. Mine isn't a good picture but filling the frame does help.
For your first post/critque, I do think you have done well. Keep it up and good luck.
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