I think it's fair enough to ask tips, not everyone can do a distance or even a gnarly off road ride, every one has a start point or difficulties. I'm not too bad but seem to dehydrate or run out of steam too easy after a mega ride. Get like a hangover following post ride fatigue. Might be cos I'm tall and slim so don't retain much fat or water summat like that, good sleep, relaxing and awareness of energy consumption as stated. also where road riding is concerned outside of commuting I've yet to try it proper, hoping to pop my road cherry on a retro or tourer this summer maybe. Keep the great tips coming all.
I find my fuel and hydration needs on my road bike very different to the mountain bike. I happily badged out 48 miles on Good Friday with one water bottle and a couple of energy bars. On a much shorter off road ride I'll easily get through two litres of fluid. I've only just started road riding, so am learning as I go...but have so far really enjoyed it!
My big thing on road is keeping warm...I really struggle. On my mountain bikes I always ride in shorts, a base layer/jersey and may be a gillet or a jacket. On the road, I've really struggled to keep warm over the last few weeks despite donning bib tights, base layer, jersey, wind proof jacket thing and shoe covers.
As others have said, cadence is important but so is just relaxing and enjoying it. Don't get too hung up on the details or what everyone else is up to. You'll be fine.
2015 Stanton Ti Switchback
2006 Specialized Demo 8
2013 Specialized Allez Sport
1999 Santa Cruz Chameleon
1994 Cannnondale Beast of the East (rebuild still in progress)