Having not ridden for quite a while I feel like I'm starting again from fitness, experience and confidence levels.

I was just wondering what routes people would recommend to someone starting out.
I'm thinking of those that are a defined route (either sign posted? or with decent established navigation routes)

Over a terrain which is beginner MTB level (or maybe even gravel bike!). Scenic but not too hilly.

It would be nice to have some single day circular routes to start with (ideally somewhere that is near campsite so I can start and finish at my camper van).

Longer term then maybe will build up to 2/3 day bike packing.

I'm based in Midlands so near there to start with but happy to explore wider (esp with camper van option as above).

Just after some inspiration to help me dip my toe in again.

Anyof the Jennride routes this years event route is a belter!
https://www.trybooking.com/uk/events/landing/78139

Probably not too far away from you.. Lincoln Gravel Imp https://bikepacking.com/routes/lincoln-gravel-imp/ Really nice route ( I would say that though as I designed it ) and fits your criteria.

The Wolf Way could be a good option as it’s pretty flat-

https://bikepacking.com/routes/wolf-way/

Or maybe the Marcher Castles taster route-

https://www.cyclinguk.org/routes/marche ... aster-loop

If you'd be prepared to pop down to East Angular for the Wolf Way, then there's also the Rebellion Way too. Pretty much any of the CyclingUK routes would be suitable, depending on how much, or little, tarmac you want to be involved - https://www.cyclinguk.org/routes

For a day ride loop on easy terrain I think the western half of the Ridgeway offers some great riding and scenery, as long as it's dry and has been for a few weeks (would be good right now I expect).

If you're on a gravel bike, maybe some of this adaptable loop of just under 100k -
https://ridewithgps.com/routes/28157535

It's a fig 8 that has 4 sections of ~25% distance on then off road with a get-out where it crosses over. If you check the map there's loads of tracks and links going N-S between the marked routes, it's very easy to cut short. I used to spend a lot of time in this area. There's some good riding and it's lovely open rolling hills countryside. Loads of parking space for a van at the 2-4km point if you don't want to park in Streatley or Goring. Nice pubs there though!

Seeing as your midlands based and looking at less hilly stuff, why not do the white peak loop. This uses the old railway lines a few trails and quiet link roads. Plenty of decent campsites. Plenty of opportunities to go off piste and explore. It can be done in a day but can be split into 2 days. There's a fair few around Hathersage and Castleton / Stanage edge area, but this is a honey pot area and can get busy. It's also lumpier being the dark peak.

+1 for what Oxoman posted.