First step for 3D Artist is Modeling. According to Modeling we create any model, character, etc in 3D worldpad on any 3D software. Basically in 2D there are 2 axis but in 3D there are 3 axis. And in 3D Modeling most important thing we should follow is that during Modeling we should make sure that in modeling the face should be in quads pls avoid tris and other make the face in quad it help in other 3D production because if model has tri faces so it trouble to unwrap the model. And also during rigging and texture it doesn't give realistic.
Topology
Topology its the main thing that make model simple and realistic model. Because topology help to understand aur faces, edges and vertex and so it make easy to edit it. If topology is not in good manner model neither look good nor have good uv wraping and if uv wraping will be wrong so it trouble in texturing