To create a single jersey structure in the software, go to Stitch view
Open the stitch selector in the toolbar on the left, and select the stitches to create single jersey as below.
You can choose to only knit on the rear bed (left) or only on the front bed (right).
Select the drawing tool you need (pencil, line or rectangle) and draw. Below two examples of a small block of single jersey on the rear bed (left) and on the front bed (right).