The best thing I did to learn my camera was to take a very long plane flight and READ THE MANUAL instead of looking out the window, but from time to time, I couldn't help myself, and I looked out the window, too. ;-)
Seriously, the Nikon 5700 manual is very thick and I just sat and forced myself to read the whole thing with my camera out during a 5 hour flight from Florida to Seattle. It helped LOADS.