Follow these rules, if the error persists then ask again:
Assigning Footprints to Your Components
Generate a PCB Editor Netlist in OrCAD Capture
Set Up PCB Design and Draw a Board Outline
Create and Place Mechanical Symbols
Place your components manually or automatically in OrCAD
Set Up Differential Pairs and Constraint Manager
Create Copper Plane and Shapes
Start Routing and perform DRC checks
Setup fab drawings, dimensioning, title block, drill tables, cross section, and more.
Produce and export manufacturing data, including drill information, gerber output, assembly drawings, solder and paste masks, and other essential documentation.