When retopologizing a face 3D model as a beginner, the key steps are importing the high-poly guide, setting up references, building a low-poly base, aligning edges to facial features, and refining polygon flow.
Import your high-poly face into software like Blender (free) or TopoGun—this acts as your shape reference. Set up front/side views (or use the high-poly itself) to match proportions accurately. Start with a simple base (e.g., a half-sphere) and add edges to outline eyes, nose, and mouth. Follow natural facial flow (circular around eyes, straight down the nose) for even polygons—critical for later rigging. Use tools like "Snap to Surface" or Blender’s "Shrinkwrap" modifier to keep the low-poly stuck to the high-poly shape.
For beginners, practice with simple faces first (e.g., basic human features) before complex details. Delete the high-poly once your low-poly matches the shape.