Answer: Le premier d'avril. Il fait beau!
Je rêve d'une promenade sur la plage.
On veut mettre un poisson sur le dos.
Méfiez-vous des poissons rouges. Soyez sage!
Explanation:
The traditional April Fool's prank in France is to pin/tape a red fish to someone's back without them noticing. People may start laughing at the "victim" of the prank. So, this "poem" is a commentary.
The first of April. The weather is nice!
I dream of taking a walk on the beach.
People want to put a fish on your back.
Beware of red fish. Be wise!
This will never pass as great literature, but it may help you pass.
(If I have used vocabulary you don't have in your glossary, be careful!)