Is this is good Poem ? How can I improve it ?

Angelica, it looks nice so far, but I would say focus a bit more on the structure of it. Your stanzas have varying lengths and it's distracting from your point. And remember not to rhyme for rhyming's sake. The slim and gym rhyme is cute, but it isn't contributing poetically. For fun, try to take out the word giraffe completely. See if you can convince your reader that you're writing about a giraffe without actually saying it. Good luck!