If you want to change the Story Level lines in your Section\Elevation views from Solid to a Dashed line. Bring up the Section\Elevation settings > Story Levels > Show Story Levels > choose the Dashed line type
Generally for a single story house you need to create 3 Storys; 0.Sea Level/ Datum, 1.Ground Floor & 2.Roof. 0.Sea Level/ Datum is where you construct your 3D mesh and draw your site info. 1.Ground Floor is where you Model your ground floor; walls, slab, windows/ doors, furniture etc. This is also where you ‘Draw’
To turn off story level lines in your sections/ elevations to show just what you want and not all stories, go to Design > Story Settings and untick the stories you do not want to show. In the example only the Ground Floor and First Floor level lines will show.
The Shortcut Key to go Up a Storey is Ctrl+UpArrow (PC) or Command+UpArrow (MAC). The Shortcut Key to go Down a Storey is Ctrl+DownArrow (PC) or Command+DownArrow (MAC)