Poldice for DH and getting ‘sendy’, also Woody’s Bike Park.
Lanhydrock for beginner and easy flow trails. Cardinham for an average trail centre lap.
Also other smaller bike parks like Old Hill and Chasewood for jumps or Bikepark Kernow for short, rooty trails.
As for the Penwith area, You can do a nice XC loop up onto the moors, look up the West Kernow Way for a route idea. There some fun chunky descents of the hills in that area also but some are lost to bracken this time of the year.