I come from the same exact background as you (software engineering and composition, now creating a game). I needed to learn pixel art for my city builder game but didn't have the skills.
First thing you need to do is steal your color palette. You can paste in any image to Asperite and create a color palette from it (it will pull every distinct color in the image). Alternatively, if you want fewer colors from the image, download paint.net and color-quantize the image. This will limit the color palette/colors used in the image to what ever number of colors you set it to. Another option is https://lospec.com/palette-list. I stole the color palette from Roller Coaster Tycoon for my game, since I love their colors.
Next step is steal pixel art, sort of. Zoom in on the pixels and copy the patterns / pixel placement, then modify (move the pattern elsewhere, adjust for different look, etc).
Now you're an artist.
Edit: And another tip, cut out parts of a scene to get the color palette specific to the object (e.g. a tree). Will help you organize larger color palettes (like RCTs, which is around 256)