The D200 ain't obsolete, no more than I am, just because I'm not young anymore!
In processing you start with white and black points and colour temperature (white balance).
The white balance can he helped by checking the histogram on the screen immediately after making the exposure. If the data is all cramped to the left or right of the screen then you need to either increase or reduce your exposure. If you got your best exposure then you MAY be able to improve it by adjusting the black and white points in Lightroom. Hold down your option key, (not sure about Windows command) then adjust the white or black sliders until the black screen only has little white specks and the white screen until there are just a few black specks. Sometimes these settings need re adjusting without the option key held to get the 'feel' you are looking for. By recording the exposure an an NEF you will have a greater range of adjustment.
For the colour temperature click the white balance eye dropper on what you think should be a neutral grey or black part of the image, sometimes there isn't one, you have to get it as near as you can then adjust the blue-yellow slider to taste, and perhaps a tad of green-magenta adjustment if it needs it.
That's a very quick first step to adjusting any image.
Your photo looks a little grey, I suspect it needs the black and white points setting. The histogram is your best friend.
If you want to do much black and white pictures then suggest you try NIK Filters, they are or were free for now. They give a nice range of adjustments to choose from presets.