I'm still relatively new to this cycling lark (returnee after a 15 year hiatus) and have learnt a few things the hard way.
1) Don't go hell-for-leather early doors. You'll burn out and turn into a puddle of goo. Slow and steady is better (and less embarrassing)
2) If at all possible, try and go outbound in a headwind and inbound in a tail wind.
3) Find a pace that's comfy and well within yourself. Use a lower gear than you think you need - it really does help.
4) Allow yourself recovery time between each ride. It's more fun when you don't ache all over.
5) Speed and pace comes with fitness. I started cycling again mid-August, and it's only been in the last couple of weeks that I've been knocking serious time (like 10, 15 minutes) off the routes that I normally do without even thinking about it.
6) Just go out and enjoy the great outdoors.