Over the past ~15 years, I've gone from: Premiere 1.5 to FCP7 to Avid to Premiere CS6 to FCPX to Vegas to Premiere CC. I didn't really have problems working with any of those programs (well, maybe except Avid). Over the past 4-5 years, I've also done a few test projects in Resolve. I just could never get the hang of it. I always had the feeling like I would need to start from scratch to be able to properly work with it. And I haven't (yet) had the energy, desire, curiosity, and/or need to do so.

Maybe other people have had different experiences and taken to Resolve quite easily, but my approach would be to find some kind of structured class, basically to first and foremost work on understanding the program and its nuances rather than trying to learn by doing.

(For reference, as it may be relevant: I'm not so much a "professional editor" but rather someone who sometimes edits professionally. Some years I will do a lot of editing and churn out 70 videos and some years it will be more like 5. None of the videos are all that complex though.)