We present a homogeneous catalog of global asteroseismic parameters and derived stellar parameters for 765 Kepler main-sequence and subgiant stars. The catalog was produced by reanalyzing all available Kepler DR25 short-cadence data using pySYD, an automated pipeline to extract global asteroseismic parameters. We find 50 new detections, seven of which are also planet candidate host stars. We find excellent agreement between our {nu}max and {Delta}{nu} measurements and literature values, with an average offset of 0.2%+/-0.4% ({sigma}=5%) and 0.2%+/-0.7% ({sigma}=2%), respectively. In addition, we derive stellar radii and masses with an average precision of 2.7% and 10.4%, respectively, and find a mean offset of 0.8%+/-0.2% ({sigma}=6%) between our radii derived with asteroseismology and those from Gaia parallaxes. Using spectroscopic log(R'_HK_) activity measurements from Keck/High Resolution Echelle Spectrometer (HIRES), we derive an amplitude scaling relation with an activity term for main-sequence and subgiant stars, which successfully predicts amplitudes with a precision of ~8%-9%. Our work is the largest and most homogeneous asteroseismic catalog of Kepler main-sequence and subgiant stars to date, including a total of 101 stars hosting planet candidates and 451 stars with measured rotation periods.