For limited space consider a narrow, shelf, 'point to point' scheme..Real RRs are squiggly P to P systems with spurs, sidings, and yards throughout...
You can can have a turntable or wye in order to turn an engine/cars back home. Or, you can merely run in reverse back through the entire line.
Some real branch lines do/did just that..This way you still get to run trains, but without a large loop and table taking up lots of room.
How is your eyesight ? N and Z can be very tough and frustrating to work with if your eyes aren't 20/20..