A cinquain has five lines and a quatrain has four lines. The only other rule for a quatrain is that it must rhyme. The pattern of rhyming is up to you.
Here is a simple example of a quatrain with an abab rhyme scheme:
King Cole rules the hall
The kids all run in fear
He shouts at them all
Whenever he gets near.
Other possible rhyme schemes include aabb, abcb, and abba. You are not limited to just these rhyme schemes. You can be as creative with your rhyme pattern as you want.
Try some of your own and post them in comments.