I am not as familiar with cinquains and quatrains; I have heard of them, but never tried to write any. So, we'll learn together! My thinking is, it's easiest to describe something you're very familiar with. Imagine that you're describing the subject as if you were there, and the memories will help you find the words:
Sailing, swimming, sunning, burning
Joyful, goofy, giggly, silly
You could try something similar to that with winter, spring or fall, too!
Sometimes a poem starts out one direction, and by the time you write the last line, you find it has ended up somewhere else entirely! That's what happened when I wrote this quatrain (in aabb form):
The lake at sunset burns like fire
Inflaming love's intense desire
My dreams of you began this way
But passion faded like the day
Not a happy ending, after all! :=)
I can't write all your poems for you, but if you have trouble with rhyming, I would suggest a rhyming dictionary--it can be very helpful! You might even find one online. When I write poems or songs, I usually just make a list of the words I'm trying to rhyme, starting with A and going through the entire alphabet, writing down every word I can think of that rhymes. You might want to try that, too!
Remember--the best way to write anything is just to start writing! Don't second-guess yourself or edit yourself until you've got something written; then go back and work on it until you like it. And don't judge your writing too harshly! It's all about learning as you go!