I've been using Darktable since the Dark Ages I suppose, back when it was still a tiny coffee-table instead of the cold- and warm- buffet-table it is today. Yes, it can be overwhelming but there are really awesome Youtube tutorials to follow. Even though I've been using it full-time since Jan.2018 I still regularly come across modules I have to learn how to use properly. Some of the below resources which I copied off the darktable subreddit are extremely useful indeed:
Beautiful and very educational workflows of what can be done with darktable. You do need a certain amount of experience to follow these videos.
If you are completely new to darktable you can literally start with episode 001 and work your way through. The first 11 will only talk about the interface, importing, views, collections and styles/presets. From that point on you should be familiar with the lay of the land. If you are already familiar with the basics you can search for and look at episodes that deal with specific modules.