The likely prospects are the contests with the best benefits for the winners at the lowest fee and most likely to want your poems. You may find that there is a condition you cannot meet. It is better to find this out before you submit than to discover it after waiting two to six months for a response. You will have wasted postage as well as valuable time. Try to read between the guidelines.
Every word often contains useful clues.
When I enter contests I read a number of contest guidelines over and over and cull out the ones that don't appeal to me or that I can't meet. A few extra minutes at this stage can be very helpful in your search for the right contest. Some contests are just attempts by marketers to get names for their mailing list or marketing pitches. Advertising and promotions can be useful, but they can also side track you from more productive approaches to promoting your writing. After you have been approached by such a marketing expert, you will learn to distinguish them from serious promoters of poetry.