First time flat hunting, feeling overwhelmed

Site visits for Noida Extension properties, what are the actual red flags to look for? I'm checking out some projects, including VPA Infratech near Chaukhandi, and honestly, brochure aur reality mein kaafi farak lagta hai. Sales guys toh sab accha hi dikhate hain. Should I be looking at water pressure, mobile network strength, ya phir nearby construction sites ka noise level? My parents keep saying check the approach road, but aur kya cheezein hain jo builder nahi batayega? Like, parking space ka scene, ya phir lift ki quality. Any specific questions I should ask the society residents if I meet them? First time buyer hoon, ab samajh nahi aa raha kya important hai.