Protoplanetary disks are the birthplaces of planets, yet our understanding of their evolution has been historically biased toward the brightest and most extended systems. In this talk, I will present the first results from the ALMA Disk-Exoplanet C/Onnection (DECO) Large Program, which provides a homogeneous survey of 80 disks around K- and M-type stars—the most common hosts of known exoplanets—across four nearby star-forming regions (Lupus, 𝜌 Ophiuchus, Chamaeleon I, and Taurus). Using a standardized visibility-plane modeling framework (galario and frank), we characterize the dust continuum emission to establish robust demographic baselines for disk sizes, masses, and morphologies. I will discuss our findings on the size-luminosity relation, showing how accounting for source inclination significantly reduces scatter and points toward partially optically thick emission. Furthermore, I will explore the prevalence of dust substructures in these "typical" disks and how they modulate the scaling relations between disk and stellar properties. Finally, I will address the impact of stellar multiplicity on disk demographics, showing that wide binaries in our sample behave dynamically as effectively single stars. These results provide the essential demographic context to link dust structures with the gas-phase chemical census of the DECO program, anchoring our understanding of the planet-forming potential in the solar neighborhood.