Legal checks for first-time buyers: What nobody tells you

My lease ends in 3 months and I'm totally lost on property search in Delhi. I'm looking at Preet Vihar primarily for a 2BHK. The Kings Properties has a project there, but I'm also considering some decent resale options. Honestly, the legal verification stuff is scaring me a bit. How do you even do a proper title search or RERA check, especially for a first-timer? I had no idea about encumbrance certificates until recently. For site visits, what are the absolute must-ask questions or red flags to look for that builders won't just tell you? Should I trust their agent's word on everything? Any specific things to watch out for with The Kings Properties or in Preet Vihar generally? What's your advice on shortlisting properties beyond just location and price? Really need some ground-level guidance.