Not meaning to be pedantic, but Wistmans Wood is on the North Moor?
If walking up to there from Ivybridge, there are various ways to go, e.g. one route could be to follow the tramway to Redlake tip, cut west to Blacklane Brook, then North to the Fox Tor area, North to Prince Hall, then up to Wistmans via Littaford and Longaford Tors. Return, via Two Bridges, Princetown for refreshments/supplies. then to the Plym via whatever route you fancy (Nuns Cross is direct/easy but of least Interest) go down to the stones at Drizzlecombe then back up to the Langcombe and up and over to Erme Pits to follow the river back down to Ivybridge.
My last post was to illustrate how far 15 miles can get you. I wouldn't suggest 15 mile days to you for 'exploring' (well, not this side of the equinoxes anyway). I'm trying to get some rough idea of the area you want to explore in an attempt to save me/anyone writing loads about somewhere you aren't intending to visit!
But if you intend to explore the moor over several/many sessions, then best thing to do is do some background reading. Alongside the OL28 map. There are dozens (hundreds?) of books about the moor. Your local library may have something. The web is ok, but hard work sometimes compared to curling up with a book.