Kill a creeper with arrows.

Craft and place a sign.

Construct one type of each tool (one pickaxe, one spade, one axe and one hoe).

Acquire diamonds with your iron tools.

Cook and eat a pork chop.

Smelt an iron ingot.

Tame a Horse.

Harvest some leather.

Construct a better pickaxe.

Use planks and sticks to make a pickaxe.

Punch a tree until the block of wood pops out.

Collect 50 Journals.