Construct an Enchantment Table.

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

Kill a skeleton with an arrow from more than 50 meters.

Befriend five wolves.

Wear a full suit of Iron armour.

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

Travel by minecart to a point at least 500m in a single direction from where you started.

Kill the Enderdragon.

Construct a Nether Portal.

Smelt wood trunks using charcoal to make more charcoal.

Kill the Kraken using a Relic in Mayday in Regular or Hardcore difficulty.

Staffing up.

Call me master.