Generally, this space is for people wanting answers to a question-- or wanting someone to write a hub on a particular subject. It would be a good idea to read the "Help" section. (Upper right corner of the page.) You can post a poem in a hub, but you might want to read all the directions first and also look at a few hubs to see how they might look.
As a suggestion, you might type "poetry" in the search box, to find some hubs with poetry, or about poetry. (You can also narrow your search to hubs.)
Good luck and welcome to HubPages!