I learned "digital" on a Yamaha 01v (the original silver face model). It has 12 mic inputs, 2 FX, 4 auxes with outputs and L/R. I'd been an analog guy for 30 years.
The $400 spent on that 01v was tuition at DigitalSkool. I set the mixer on my desk, opened a Dr. Pepper and started plugging things in. I pushed buttons, turned knobs and otherwise did stuff until it quit making sound. Oops. Back to Scene Memory, recall the first preset and was back to factory config. Then I opened the manual, figured out what my level of ignorance was and started practicing all over again.
Then I put it back in the case and put it out in the shop mixer pile. It sat there for about a year. Finally disgusted with myself, I took it to youth conference with the mindset that I was using this... thing... unless my ignorance was a show-stopper. I had an analog FOH rig in the van, but my goal was to leave it there.
What I learned from both the office time and first gig: setting up a highly configurable digital mixer is a lot like setting up an extensive analog FOH rig for the very first time. Nothing is patched, none of the "cool stuff" is programmed, and you can't assume that an inserted device is active (did I push the "IN" button?). In many respects it's intimidating because, even in analog, that level of setup is something we only do once or twice, or it's something that has evolved over use. The next thing I learned is that if I have inputs that span layers, I need to give some advance thought about where I want my inputs patched (or become acquainted with the mixer soft-patch capability). The final thing was that I needed to accept that I wasn't as fast on the new mixer and that familiarity would eventually happen.
Other than those things, mixing itself turned out to be much the same. The hardest thing to do is EQ with your ears and not your eyes. Trust me.
So when you look at a new digital mixer I suggest you download whatever off-line software the manufacturer has. Use that to examine features, build soft patches and routing, etc. and familiarize yourself with whatever features are included in the off-line editors. When in front of the mixer, remember this: "it's in here, somewhere." Take your time, be methodical and you'll find what you're looking for.
Have fun, good luck.
Tim Mc