BeerCan is right. You don't have to go far form Trail head to hit any of the trails there. Everyone follows their own path. I am a B-/B rider and do up the black diamond trails. I don't do the double black diamonds (yet) and still avoid some of the "hard" sections on others.
For the online trail maps visit:http://www.floridastateparks.org/alafiariver/docs/WebsiteBikeBrochure.pdf
My flow at Alafia when i am alone is as follows:
Warm up with my favorite of all trails in the world.... Sandpine. Then do: Rock Garden, River loop, south side of Bridges, North Creek, take double track road to north side of Bridges, double track road to Rollercoster. If time allows it, I do it again of course.
If you can ride the double dimond courses then you can do almost the same as above but this way: SandPine, Rock Garden with hard sections (shelly's loop, Frank's Loop), River Loop, South side bridges with hard section, Gator back (if open. Curently closed), North Creek, North side of bridges, Rabitt Ears, Rollercoaster, Moonscape.
Have fun and stay safe....