If you are new to Dungeons and Dragons (5th edition)
For Players:
We’re big fans of using D&D Beyond to build characters. It’s free, simple, and a takes away a lot of the complexity in making a character and doing all counting and bonuses. It’s a videogame-esque character creator - you pick a race, class, and some ability score values and you are off. It also has the full Basic Rules for players and DMs to learn the basics of the game.
(We use D&D Beyond for our weekly D&D campaign - The Adventurer’s Guild)
For Dungeon Masters
Now this is a bit more complicated. You actually can start with no purchases (maybe just a dice set, but you can use an app for that if you are really on a budget). You can find a ton of adventures online to start players off with, and everyone can refer to the free Basic Rules.
Our suggested approach is probably buying the D&D Starter Set(amazon.in link). It comes with a dice set, a rulebook, character sheets, and a great adventure for DMs to run for beginners called The Lost Mines of Phandelver. Everything you need for about 6-12 sessions (or around 50-60 hours) - plenty of time to know whether D&D is for you (and your party).
There is a more recent box set called the D&D Essentials Kit(amazon.in link) which has more in the box. It comes with a dice set, a DM screen, character sheets, cards to track initiative, conditions, items, and quests, along with an adventure called The Dragon of Icespire Peak. While the adventure is a little meh (and hard to run at times), the value of the box is super good. Especially since it also includes a code for the digital copy of the adventure and a code for 50% off the digital copy of the Players Handbook on D&D Beyond (which is otherwise ~$30).
If money is no object, then you can buy the three core rulebooks(amazon.in link), and an adventure book of your choosing.
You can also get dice sets and dice trays from our good friends over at The Bored Game Company at a reasonable price.