read:
- layers - to show each level separately when working
- color track - sometimes that helps when working with multi-levels
- elevated track to set the height of the track on a layer
- setting grades - to select and set the grade of the transition between layers
I tried to copy and paste to one file. I don't know how they are supposed to connect or even if it is multi-level.
You'll need a barn if this is in O. It's 10 x 20 in HO , so a guesstimate in O would be at least double that - 20 x 40.