I don't teach photoshop. Any young kids working in web-designing have those skills. If all you want to learn is photoshopping, then what is the difference between photographers and others?

It is a tribute to the modern high megapixel cameras that you are able to crop so much. The bird in the frame is tiny and still you want to crop it and show it big. That will ensure loss of details.

People often ask me from how far I can shoot, when they see my long lens. I tell them that the camera and lens is not like a sniper rifle that you can fire from several kilometers. Your lens will give you good results if the subject is within its range. Remember the famous words of Robert Kapa "if your images are not good enough, then you are not close enough". No amount of post processing can help in creating a great image after massively cropping an image. Also, the long distance will reduce the quality due to haze, and often heat waves.

Having said that, you have to realise the strength of your equipment and shoot within that. In the image you have posted, it shows the habitat. Unfortunately, the habitat is not well detailed as you have used f5.6. If you would have used a narrow aperture like f8-f9, then more areas would have been within the depth of field. Having said that you still need to be close to the subject.

Creating environmental compositions is not easy. So you can put in an effort to master it. Just take it as a task that for the next one month everything that you will click will be wider in composition at f8 or f9 and as close to the subject without cropping. We don't improve unless we challenge ourselves.

The bird is at the centre of the frame. That makes the image static. Moving the camera a bit to the left would have helped in a more off centre composition. Also less space at the bottom and more at the top would have strengthened the scene.

And lastly, before clicking we need to think as to why we are attracted to the scene. Or what part of the scene we are attracted. If you like the scene, then proceed to photograph it and use the settings accordingly.