Got my new keyboard, typing this message at close to zero wpm. 
I see some really neat things on this forum, such as plugins like the one described in “New plugin: water/wavepool LED effect”. But I have no idea how to get started. Is there a guide to get started on building and installing firmware and plugins?
The wiki is a good place to start 
Customizing your layers is the suggested first step. Keep typing and you’ll soon find a few mistakes that you consistently make, such as typing = when you want a -, or hitting the PROG key and expecting an ESC. I’ve found that is a strong clue to customize the keyboard and turn my persistent mistake into the correct behavior!
That’s where I started. Oddly enough, I find myself slowly reverting to the stock layout. As my fingers get used to the spacing, the original layout feels increasingly “natural”. Other than adding some qukeys/dual use modifers, I’m nearly back to where the beginning!