Be aware of clipping in post-prosessing. Learn what it is, what it does, how to recognize it and avoid it. Many opinions on this, a lot of youtubers are sloppy. THOU SHALL NOT HAVE CLIPPING AT ALL! Stick to the Crop, Levels and Curves tool, with the aid of the histogram, in that order, to the end. If you need to adjust colors or remove noise, that's the last step.
I use Gimp, mostly because I'm a Linux guy, but I've watched many tutorials on Photoshop. In my humble opinion, Gimp seems more mature and grown-up, with the menus and tools more logically ordered. It does what Photoshop does, and more. With the Gimp G'Mic plugin-suite installed alongside I can't think of any rival.
Take notice of the "Copy Layer"-trick! You will see some using this. A quick and handy way of Undo/Redo - new to me, now I use it all the time!