Unlock the Level 2 missions from the Town Sage and then complete the quest entitled, "The Great Jungle Kut-Ku." With the training school open, you can fight the Kut-Ku and other monsters in a practice match with limited weapons.
Unlock Gallery Movies
Pretty simple to unlock, these movies can be accessed by encountering certain creatures in the game:
Avian Master of Jungle - Yian Kut Ku in the "Great Jungle Kut Ku" Quest
Blue Hunter - Velociprey in "Your First Monster Hunt" Quest
Divine Providence - Rathalos in the "Rathalos Urgent" Quest
King of the Heavens - Rathalos in the "One Star Egg Carry" Quest
Lao-Shan Lung - Find Lao Shan Lung
Menace in the Sand - Cephladrome in the "Land Shark" Quest.
Poison of the Swamp - Gypceros in the Swamp area
Shepard Encounter - Velocidrome in the "The Formidable Velocidrome!" Quest
SupremeRulerInferno - Find Gravios
The Lone Black Wolf - Yian Garuga in the "Slay 20 Velociprey" Quest
The Phantom Beast - Find Kirin
TheAncientPiscine - Find Plesioth