It's good to have a go at black and white imagery.
I'm interested as to why you decided this scene would be a good candidate?
Good monochrome images rely on shape, tone and texture for their impact. You have a nice rocky foreground and that figure on the hill is a strong focal point.
however, the dull conditions mean the overall result is grey and not exciting (to view). A dull scene is dull in colour, too. What can be done in mono is to boost contrast, something that would make a colour image look unnatural but in mono would be appealingly punchy.
The best approach is to take the image in colour and convertt to mono using software, the Channel Mixer being a good start. That's what it's called in Photoshop and I think Elements too, though other packages may have slightly different names. This allows you to vary the amounts of red, green and blue in the image so you can differentiate tones.
For example, someone in red clothing with a backdrop of green foliage woul dbe very similar in grey tones. Using the Channel Mixer you can vary the amounts of red and green so the person stands out from the backlground. Even then, you may need to boost contrast using Levels or Curves.
Shooting in colour allows you to capture all the image information for a better end result. Letting the camera create a mono image throws a lot of information away before you start.
There is a little texture in the sky here, Yu can selectively darken and boost contrast here too to bring back some mood.
By all means shoot a mono image in camera first and review the image on the screen, as this will help you 'see' in mono. then shoot a colour image and play later.
Back to the figure. It's very strong visually so I'd make more of it. It's a very dominant position being on the hill and high in the frame.
If the person was under your control you could try different positions - the middle ground or the shoreline would be good places to try too.