Cosmic Noon in 3D:Lyman-alpha forest has emerged as a potent observational tool for probing the gas dynamics within the Intergalactic Medium (IGM) during cosmic noon. Surveys such as BOSS and DESI, which analyze the forest within the spectra of background quasars, have recently provided unique insights into cosmology and relevant astrophysical processes, including HeII reionization. Conversely, Lyman-alpha tomography surveys enhance the density of background sources by observing the more abundant Lyman Break Galaxies (LBGs), furnishing a 3D map of neutral hydrogen at redshifts around z ~2-3 with exceptional spatial resolution of approximately 2 cMpc/h. Furthermore, Line Intensity Mapping (LIM) represents a novel technique aimed at detecting the collective emission from all galaxies across the sky. In my thesis, I will delve into the indispensable role of state-of-the-art cosmological hydrodynamic simulations in modeling these observations, constraining cosmology and elucidating the intricate connection between galaxies and their gaseous environment on IGM scales.