If you don't know how to play croquet, here's how you can learn. If you already play croquet, here's how to improve your game.
Learn How to Play Croquet
For the serious sport of croquet learn to play Golf Croquet. This will teach you how to swing a mallet, hit a ball, run a hoop, and the order in which the hoops must be run in Six-Wicket Croquet. Then learn to play International Croquet. This will teach you how to make two-ball shots, and run breaks. Then learn to play American Croquet. This will teach you about sequence, and carry-over deadness.
The USCA also offers classes that will teach you how to play croquet.
Or, you can try learning on your own.
Improve Your Croquet Game
Or, visit some of the many other coaching websites.