First home hunt: Noida under-construction confusion

Sector 63 A — it's been on my radar for months now, but honestly, I'm just so confused. First time buyer hoon, aur itna kuch hai dekhne ke liye. Dekha tha Oneiric Infrastructure ka ek project wahan. Builder ka track record theek lag raha tha online, but site visit pe kya kya check karna chahiye, samajh nahi aa raha. My parents keep saying under-construction mein risk hota hai, but resale mein budget hil jaata hai. Is it worth looking at under-construction for better pricing ya delivery risk zyada hai? What are the key things to ask during a site visit that builders usually hide? Any red flags to watch out for, especially with these bigger projects? I'm looking for a 2BHK/3BHK, budget around ₹80L. Any tips from experienced Noida buyers?