Hi Trevor !
Sorry I missed your question .
Lightroom is another product from photoshop and yes it's subscription which I don't like but it's $171 a year which works out to be 46 cents a day . I have intermittently done a lot of photography over my lifetime and although I was never into Photoshop , Lightroom really is quite an impressive program .
The Photoshop subscription comes with Lightroom Classic .
https://www.adobe.com/au/creativecloud/plans.html
I can't find a good tutorial about it that is specific to astrophotography but you just start experimenting with each tool or slider until you become familiar with it .
If you have a group of stars that are too bright but the rest of the photo is good , you can draw a circle (radial filter) around the group and reduce the Exposure or make other corrections to that one location .
If there is part of a Nebula (cloud) that is dull and you think needs highlighting , big or small , just draw a circle around it and make your corrections .
There is a Saturation slider which you may use for a final boost but the colours are also split into Red Orange Yellow Green Aqua Blue Magenta Purple . It will only enhance colours that are present , it won't introduce extra colours . So if you need to boost the Red or Orange or Blue , you can adjust that individual slider .
The picture above of the Tarantula nebula contains the Homunculus . In the original picture it was overexposed , I just drew a circle around it and dropped the exposure .
Adjustments you can make .
Basic
Temp Tint Exposure Contrast Highlights Shadows Whites Blacks Texture Clarity Dehaze Vibrance Saturation
Tone Curve
Highlights Lights Darks Shadows
Split Toning
Detail
Sharpening adujustments
Lens Correction
Vignetting
There is also a changable zoom function to work on those small areas .
There are also a row of tools you can use . I mostly use the radial filter .
When your done making corrections , open the file in photoshop "with Lightroom adjustments" and "save as" .
In the end it's all very simple and intuitive but you'll need to get used to it . Any corrections are done instantly and can be "reset" .
Sorry for the late reply : )