valuation guide

guys i am pretty much new here can u tell where do i learn this dcf valuations and all i have zero knowledge of this and i pretty much struggle trying to value a company as a result i have entered some great companies (using fundamental , sector analysis etc ) at not so great prices...had a great run during the bull run post 2020 (27% cagr since 2020-sept 2025) but now these companies are returning to the intrinsic value i see my portfolio getting battered in the recent stocks that i bought also are these methods even effective ? never heard buffet talk about such technicalities in detail he always tells the importance of intrinsic value but never tells how to arrive at one does these models work in small or mid market cap as well ? which are very sensitive to events/news... and does it fit well in the indian index as well (one of the most overvalued index in the last 2-3 yrs imo) your inputs are highly welcomed !