Out of the box I don't find the default screens all that useful. Over the years I have tweaked my Garmin screens to show the most useful information at the right time whether I am riding for fun, racing, or training.
Here is how I have mine set up.
Screen 1: Riding For Fun Screen.
Screen 2: General Training Screen: Laps, HR, Power, Cadence, Grade.
Screen 3: All Things Power. Great for non-interval rides with targeted power.
Screen 4: Intervals With Power. Power zone front and center.
Screen 5: Intervals with HR. I use this screen during races.