Draw a Path with the Pencil Tool
Pencil is a freehand drawing tool. It creates a path that follows your finger as you draw. The Pencil tool is, in fact, the Draw tool that draws with a stroke.
To activate the Pencil tool, tap on the Draw icon in the Tools panel. Before using it, make sure that a stroke is selected in the Appearance panel.
Settings of the Pencil tool are located in the Control panel. They are described in the Create a Path with the Draw Tool section.
The Pencil tool supports all of the profiles that you can select in the Profile pop-up menu.
The Pencil tool can work with Apple Pencil that has a pressure sensor. By applying different pressure, you can change the thickness of the stroke while you are drawing. To enable the pressure sensitivity, activate the Pressure option in the Control panel. Parameters that influence drawing with variable pressure are located in the Control panel.
Once you finish drawing, you can modify the created graphic. To edit the path, use tools and methods described in the Edit a Path section. To change how your graphic element looks, use the Appearance panel.