Darktable offers a few really powerful, generic tools that you can use in different ways to get different effects – things like equaliser, parametric masks, LAB curves, etc. It makes little sense to use it without reading up on some of those more advanced tools first.

Lightroom, in contrast, focuses more on offering a small selection of pre-defined tools for specific purposes. But once you want to do something outside of that (parametric masking is one of those things I really missed) you're shit out of luck.