Topics in String Phenomenology

We consider two questions in string ``phenomenology.‘’ First, are there any generic string predictions? Second, are there any general lessons which string theory suggests for thinking about low energy models, particularly in the framework of supersymmetry? Among the topics we consider are the squark and slepton spectrum, flavor symmetries, discrete symmetries including $CP$, and Peccei-Quinn symmetries. We also note that in some cases, discrete symmetries can be used to constrain the form of supersymmetry breaking.