I agree with @michaelmirn Mesh Modeling Bootcamp is fantastic for topology intros. Learning the cookie and the face bust is probably one of the basic intermediate steps for intro to topology. Another good practice after doing that is trying to implement all quad junctions in various ways and learn/practice placement of 5 sided poles and learning to move them around for better topology flow.
One really good practice is to grab a free sculpted object and try retpology on it like the Orb-Robot example.
