There’s a big difference between “Routes” and “Activities”
Routes that you create on Strava are just there for your use, to follow while you are logging rides on GPS. I don’t think that they are visible to anyone else, and they have no link to segments.
(edit : you can share your routes with people, but you have to send them a link)
Strava only uses GPS tracks from rides (“Activities”) in their database. If you want to look at other peoples rides, then searching by “Activity search” in the “Explore” section will find some. Or you can look at existing segments and see peoples GPS recordings of rides.
This will all be a lot clearer when you get a GPS device and start using it!