Further reading
The TikZ manual explains nodes in Part III, Section 17, Nodes and Edges. You can open the manual by typing texdoc tikz at the command prompt or online at https://texdoc.org/pkg/tikz as a PDF document. You can read that chapter in an online HTML version of the manual at https://tikz.dev/tikz-shapes.
Furthermore, the TikZ manual has a comprehensive reference of shapes in Part V, Section 71, Shape Library, also online at https://tikz.dev/library-shapes. It shows all shapes with anchors and many customizations.
The tikzpeople package documentation is available at https://texdoc.org/pkg/tikzpeople.
The home page for the epstopdf tool is https://tug.org/epstopdf/; there, you can find links to download it and documentation.
