Nothing’s marked at all (outside of the bike park area). I’d hope for a local to chirp up and offer to show you round to be honest, though having said that…
I would say it’s going to be a bit of a muddy, trail-knackering slog-fest if the forecast of rain for Mon & Tue is right. Normally wet conditions can be mitigated by concentrating on the bike park stuff but it doesn’t sound as though that’s what floats your boat.
I think I’m right in saying the only method of paying for a day permit is to do it in person to a warden, so be prepared to pay if you see him but I wouldn’t fret over it.