We propose the first coherent, statistically-significant study of the physics and chemistry of young protostellar systems, where disks are still accreting material from the surrounding envelope (Class 0 and I sources, PI: Caselli), and of more evolved, isolated planet-forming disks (Class II sources, PI: Henning). This survey offers an unprecedented chance to study the initial conditions for disk and planet formation through multiple evolutionary phases. The unique capabilities of the PolyFiX correlator and upgraded NOEMA will provide information on the angular momentum, density, temperature, turbulence, and chemical composition in the Class 0/I and II objects, linking different stages of star and planet formation. We will target 32 Class 0/I protostars in Perseus and 8 Class II disks in Taurus for which extensive supplementary datasets exist. Brighter Class 0/I sources require 8 hours per source, and less bright Class II sources require 30 hours per source (totaling 520 hours via Guaranteed and 100 hours via Open Time). We will use the NOEMA C- and D-configurations and spectral settings at 201-280 GHz (1 mm).