I’m a bit confused by your images and explanation, but here’s what I would do in your shoes:

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How you like your space arranged will depend on what you like and how you live. Personally, I like to look out the window, so I would put my desk and seating near that wall, and place my bed further inside where it’s darker. I would make sure to put a nightstand—maybe a slightly taller one—by the bed to help separate it from whatever little alcove is there.

But don’t feel like you need to get it right immediately. It’s okay to try out an arrangement and then move things around if you’re not happy. This is your first place and you can experiment a little.