You'll need to go into the Nether and mine to find Ancient Debris. From there, you'll have to smelt the Ancient Debris into a Furnace to get Netherite Scrap. You'll need to combine four Netherite Scraps and four Gold Ingots in order to get one Netherite Ingot.

How much is a full set of Netherite?

In total, you will need 36 Netherite Scraps and 36 Gold Ingots to make the entire set.

How do I turn ancient debris into Netherite?

You can throw the ancient debris into a furnace, or blast furnace to save time, and then they will turn into netherite scraps. You get one netherite scrap for each ancient debris, but to make a netherite ingot you'll need FOUR scraps.