Teen Ink has a very clear online submission form, and a great track record of publishing student work.
"We are a small staff, and we receive 200-300 submissions each month; however, we strive to respond to regular submissions within 10-12 weeks. We do offer an expedited submission option for an additional fee, to which we respond within two weeks."
"You are invited to send your poems, stories, essays, artwork, and also photo essays for our consideration. Please note that we’re now accepting submissions for publication both in the print issues and on our website. All art—paintings and drawings, and photos—can be published in full color on the website. Youth Awards and other contests and special features have a few deadlines as below. We will publish the ten winners of the Youth Honor Awards and Haiku/Tanka Contest in our Awards Issue. Please read the details by clicking on the Youth Awards. The 2024 Contests will be announced later this year."