Correct, you will want it copyscape protected before you publish it anywhere online. Also this would not be your best means in increasing exposure to your work, as poetry usually does not fair many views on content websites...You will want to have it submitted to poetry, or creative writing sites. However they will more than likely require first American publishing rights, or electronic rights for X time (or perm). So make sure you read the copyright on any site you decide to post it to.
I hope this helps a bit, I wish you the best of luck.