In reply to 'Hilda':
Yeah, what ^^^ they said.
I see you're over 40, so you're the right age.
However, you need to develop the male pattern baldness to have any chance of being a fell runner, and grow a beard.
Seriously, I got into it via MM's and, like you, consider myself a very average runner (10k road in an hour). But it's so much more than times and distances, I just love it when I get in my stride and feel like I could run all day. I can probably run 30k in the hills but wouldn't dream of doing that on the road.
Good luck with it, go small to start, something manageable and build up. Coastal runs are great as a starter as they're very up and down but not one or the other for great distances.
Keep posting on here how you get on.