Here is the full list of all 24 Monster High: New Ghoul in School achievements.
Complete first Fearleading Event.
Complete first Council Event.
Purchase Clothing Online.
Find and use a Locker Code.
Complete a Fundraising Event.
Collect all Cheer Steps.
Leave for school with a Tidy Room.
Ring the Bell in the Bell Tower.
Have over 1000 Spirit Coins.
Upgrade the Creepateria.
Upgrade the Casketball Court.
Complete Fashion Club Events.
Complete Environmental Club Events.
Complete Robotics Club Events.
Complete Cooking Club Events.
Complete Comic Book Club Events.
Complete Standalone Events.
Find all the Shortcuts.
Meet all the characters in Monster High.
Collect all Dusty Pennants.
Collect all Spirit Spiders.
Save the School!
Obtain All Clothing Items.
All other Achievements Complete.