Here is a list of some publishers that specialize in poetry by young and emerging poets:
Button Poetry
YesYes Books
Finishing Line Press
Sibling Rivalry Press
Black Lawrence Press
Tupelo Press
BOA Editions
Milkweed Editions
Four Way Books
Alice James Books
It's worth noting that these publishers may have different submission guidelines and preferences, so be sure to read them carefully before submitting your work. Additionally, it's always a good idea to research the publisher and read some of the books they have previously published to get a sense of whether they may be a good fit for your work.