Easiest access & parking is at the top carpark at the water tank on Arthurs Seat Rd only about 200 metres west (towards the top of the hill) of the Main Creek Rd intersection (fairly major side road, can't miss it). There's a trail map sign just inside the fence there. Alternatively you can park opposite the shops in Boundary Rd at the bottom of the hill & access the trails through the Hilllview Community Reserve, just follow the path up past the BBQ shelter to get to the trails. There's also a map sign there as you get up to the edge of the park. There is also a map sign at the main track junction toward the centre of the park.
Tracks 1 (Pink Line), 2 (Rock Salt) and 3 (Slippery Gypsy) are separated by short sections of fire road, but from the end of Slippery Gypsy at the central junction the rest of the trails radiate & you can do a few loops with virtually no firetrail. A couple of notes: about halfway down Rock Salt there is a t-junction, take the left, as the right is a short exit link out to the central fire road. At the exit of Rock Salt turn left onto the fire road, then at the junction just a little way along turn right to pick up Slippery Gypsy; the left branch will take you straight down to the main trail junction.
Within the main network of trails there are no walkers-only trails; the nearest is the Friends Track which runs from the fire trail between Pink Line & Rock Salt along the side of the hill toward the outlier trails Crits, Deadwoods and Charlottes. Despite being officially walkers only, it seems to get more bike traffic than foot traffic.... The official link is track 12, which runs just inside the fenceline from the top trailhead to the fire trail which takes you down to Crits & Deadwoods. There's a gate across the road a way down around the curve, but there's a bypass trail up the bank on the left.
I would advise against Charlottes if you do not have a support crew to pick you up from the bottom; finding your way back out to the rest of the network is not easy without local route knowledge, and even if you do know the ways It's quite disjointed from the rest, so adds a decent chunk of time & distance to the ride.