Minecraft wiki entry for Combat, associated text: Diamond or netherite sword with Sharpness enchantment
Iron, Diamond or Netherite axe with Sharpness enchantment (only in 1.9+)
Shield (preferably with Unbreaking enchantment and in 1.11+)
Armor (preferably diamond or netherite) with protection enchantment, you do not need a high-tier armor if you are an experienced Minecraft fighter
A few potions of Regeneration/Instant Health II
A few potions of Strength II
Great saturation and hunger-filling foods, such as steak, cooked porkchops or at best, golden carrots
golden apples or enchanted golden apples