When you open a new part document, first you create a sketch. The sketch is the basis for a 3D model. You can create a sketch on any of the default planes (Front Plane, Top Plane, and Right Plane), or a created plane.
You can start by selecting:
- Sketch entity tools (line, circle, and so on)
- Sketch tool
- Planes
- Extruded Boss/Base or Revolved Boss/Base on the Features toolbar.
You can also create a sketch on a flat surface, a spline on a surface, or the face of a solid.