Co₃Sn₂S₂ has received immense popularity in the condensed matter physics community because it is both a promising candidate for a magnetic Weyl semimetal and a non-Bravais Kagome lattice ferromagnet. So far, a careful correlation between the surface and the bulk properties, including structural, magnetic, and electronic properties, has yet to be explored comprehensively. In this talk, we will present our selective studies of the surface and bulk properties by conducting optical rotational anisotropy experiments of second and third harmonic generations (S/THG), respectively, using near-infrared wavelength light. We will also use light polarization to distinguish between the magnetic and the structural/electronic contributions in both linear and nonlinear S/THG optical measurements. Finally, we will carefully track the temperature dependence of both the linear and nonlinear optical responses across the magnetic critical transition temperature.