Our Solar System was born from a dark and cold cloud made out of molecular gas and small dust particles. Thanks to powerful telescopes, we can now study in detail these clouds, their chemical ingredients and their evolution. We can then reconstruct our origins. Interstellar molecules are unique tracers of the dynamical and chemical evolution of star and planet forming regions. Thus, astrochemistry is crucial to test theories and shed light on our origins. In this talk I shall review the chemical and physical structure of interstellar clouds, where stars and planets are formed, as well as theoretical work on protoplanetary disk formation and early evolution. Links to our Solar System will be made.