You can create a new schematic from File | New | SIMetrix/SIMPLIS Schematic
Alternately, you can create a new schematic by using the Create New/Open quick link from the MPLAB® Mindi™ Analog Simulator Welcome Page.
By pressing the Ctrl+G key combination, you can see all models installed.
Microchip Technology models are available from Place | From Microchip Library. These models are compatible with SIMetrix or SIMPLIS schematic types.