Craft a Brewing Stand using 1 Blaze Rod and 3 Cobblestone
Get Blaze Powder to fuel the Brewing Stand
Get Water Bottles
Brew Water Bottles with Nether Wart to make Awkward Potions
Get a Golden Carrot
Brew Awkward Potions with Golden Carrot to make Night Vision Potions
Get a Fermented Spider Eye
Brew Night Vision Potions with Fermented Spider Eye to make Invisibility Potions
Add Redstone Dust to extend the duration if desired
Use Glowstone Dust for a stronger effect only if needed for other potion types, not invisibility
Drink the potion to become invisible
Use a Splash Potion or Lingering Potion version if you want to affect others or create an area effect