Wot Lee said...
Tweaking curves isn't really beginner stuff, and I think you'd struggle to find a beginner (i.e. free) software that does that (or does GIMP, which is not really simple at all?)
I used to love Lightroom, but it rapidly became obvious that I was at risk of dying of old age whilst waiting for it to process a batch of photos. It struggles desperately with large image files, and its refusal to use more than one processor is a pain. I went to Capture One Pro, which is designed to cope with Phase One's 100MP raw files. not free, but very affordable for Sony users.