Destroy a Ghast with a fireball.

Enter an End Portal.

Construct a Nether Portal.

Create an Iron Golem.

Deal nine hearts of damage in a single hit.

Catch and cook a fish!

Gain the trust of an Ocelot.

Smelt wood trunks using charcoal to make more charcoal.

Swim in lava while having the Fire Resistance effect.

Acquire 30 Emeralds by trading with villagers or mining.

Cook and eat a pork chop.

Build some bookshelves to improve your enchantment table.