The cycling path is below Eterna City. You need a bike to get in there.
its right bellow eterna city
near the Pokemon league
You get it from Dawn(or brandon) at the end of cycling road
The cave under the cycling bridge
It is on Route 224
Get a Gible in the cave below Cycling Road, and evolve it twice to obtain Garchomp.
The 'Cycling Road' is between Eterna and Oreburgh (it doesn't go directly to Oreburgh, but that is the nearest city).
a girl at the end of wayward cave under cycling road
near Ravaged Path
there are some on the path to floaroma town.
its the path next to the Pokemon league on the right
Yes in turnbackcave on the spring path after you beat the Pokemon league