“The Dhandho Investor” by Mohnish Pabrai contains some simplistic explanations on how a DCF is done, in case you’d like to check that out.
I would also suggest the following course: https://www.asimplemodel.com/model/3/discounted-cash-flow-model/
ASimpleModel is an amazing tool/website to learn financial modelling. It has courses and tools to learn financial modelling step-by-step. In fact, it’s being used by several famous MBA institutions around the world (Harvard, Wharton, Berkeley to name a few). Their annual subscription charges are around $2.75 i.e. ~Rs. 2400 pa or ~Rs. 200 pm, which I think is a low price to pay for such a resourceful website.