Sarbajit Chakraborty
Tony, I was on Linux for a long time, so here's some (not a lot of details) idea of the software that I used:
1. GIMP - Layer based photo editing. I personally found it hard to get into and difficult to manage. I also used it in 2012-2014, so things may be a lot better now
2. RAWTherapee -- Used it briefly, before I switched to Windows. I think probably the most polished and easy to learn of the editing software that I used. Also, I am slightly biased towards this, as it had the best capability to hand Fuji's X-Trans sensor. Very good at handling detailing, de-mosaicing, and adjusting for aberrations. However, not good for file management (like a Lightroom like system), and for fast workflows.
3. Darktable - Linux's answer to Lightroom (IMO). Has a lot of different modules like Lightroom. Has the steepest learning curve, but very good as a long term organizer. I only switched away from it, after spending a lot of time to learn, cause it didn't handle Fuji well.
I would definitely give #2 and #3 a try. Darktable is more resource intensive, but also has similarities to Lightroom CC, so it's a transferable skill (I think).