It wasn't all that long ago that I used to think the auto enhance features of programs like Picasa were sufficient to improve my images. If I could invent a time machine, the first thing I would do would be to go back in time and yell at myself to start using Lightroom (okay well maybe after I tell myself to buy Apple and Adobe stock, along with some Bitcoins).
I learned through a combination of friends with similar interests, blog posts, and tutorials. Here's a good compilation of links to get you started. If you don't believe me, check out the before and after examples below (may not work correctly on a mobile browser). All edits were done with basic Lightroom tools and didn't require any complex masking, layering, etc. Some edits are subtle, but often that is all it takes to make an average picture great.