Kill the Wither.

Swim in lava while having the Fire Resistance effect.

Use a saddle to ride a pig, then have the pig get hurt from fall damage while riding it.

Construct a Dispenser.

Team up with an axolotl and win a fight

Trim with all the following smithing templates at least once: Spire, Snout, Rib, Ward, Silence, Vex, Tide and Wayfinder.

Use the Totem of Undying to cheat death.

Using the Frost Walker boots, walk on at least 1 block on frozen water on a deep ocean.

Craft and place a sign.

Cook and eat a pork chop.

Construct an Enchantment Table.

Bake a cake using wheat, sugar, milk and eggs!

Use planks and sticks to make a hoe.