The book by Andy Lennon is good for fundamentals, just don’t take some of his stuff too serious, and be aware that some the equations are wrong.

There is only thing one can generalize about airfoil shape if we constrain the foils to flat, semi, and symmetrical. The only generalization is the symmetry of positive vs. negative angles of attack (AOA.) It is not possible to make any other conclusion, including stability, wing loading, any lift to drag assumptions, stall characteristics, etc. without knowing the exact airfoil shape, size of the chord, and the speed of flight.