For the sake of writing poetry, introducing yourself to its various forms (classical and more contemporary), and finding excellent examples of those forms, I highly encourage this particular Norton text edited Mark Strand.
I was absolutely NOT a poetry person until my creative writing professor who taught poetry writing introduced our class to this book. I have since begun incorporating it into my own creative writing curriculum as a high school teacher. It works wonders with my young writers, and I’ve seen many of them flourish with it.
The Making of a Poem: A Norton Anthology of Poetic Forms https://www.amazon.com/dp/0393321789/ref=cm_sw_r_cp_api_glt_fabc_D0CW5F5X9A4R07YRS72C
My favorite poetry book that I take everywhere is The Making of a Poem. It's a Norton Anthology and it's amazing. Honestly recommend reading it cover to cover if you want a foundation in traditional forms.
You need this book immediately! When I was earning my BfA in CW, poetry was a significant weakness for me, too. I had a professor teach us forms. We read analyzed and discussed even more contemporary examples of the forms covered by this book. That was super helpful to me.
Now, I’m a HS teacher of English and Creative Writing, and I use this book when I teach poetry units. I even once used it to help this young hip hop artist in one of my classes discover some new structures for lyrical expression that he later applied in his music writing, and he remains of the few kids I’ve ever seen pull off a successful sestina.
And if you are taking a college poetry workshop class, I’d be less concerned about the writing and more concerned about the workshop portion. Any good workshop teacher is grading you not on your initial draft. They are grading you on the progress you make incorporating feedback into your revisions, and on the quality of the feedback you are giving your peers on their manuscripts and in the workshop.
Keep pushing, and read more examples of you need to.
Oh! And the second link is to Poetry Foundation in case you haven’t been to it before. You can used the advanced search to search for specific themes or forms in poetry.
The Making of a Poem: Norton Anthology of Poetic FormThe Making of A Poem: Norton’s Anthology of A Poem
Poetry Foundation poetry foundation
The Making of a Poem: The Norton anthology of Poetic Forms is an invaluable read.
Otherwise, read poetry; writers read several times more than they write.
The Poetry Foundation website is a great place to start.
This book is straight fire for that The Making of a Poem: A Norton Anthology of Poetic Forms https://www.amazon.com/dp/0393321789/ref=cm_sw_r_cp_apa_i_O8vMCbZGZ7604 I am so pissed at myself that I lent it out and never got it back
Some options. https://www.amazon.com/Making-Poem-Norton-Anthology-Poetic/dp/0393321789
Then this is just a giant anthology of poems that would be a good intro into the history of Poetry but isn't going to teach anything directly because it's just a giant book of poetry. However, the best way to learn poetry is to read poetry so. https://www.amazon.com/Norton-Anthology-Poetry-Shorter-Fifth/dp/0393979210/ref=mp_s_a_1_1?ie=UTF8&qid=1529959294&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=norton+anthology+of+poetry+shorter&dpPl=1&dpID=41THNY4FF3L&ref=plSrch
I think that you could try two different approaches: You'll always have the recommendation of one poem or the other, (for which purpose I'd recommend my favorite, The Funeral, by John Donne, or you can go through a poet, one collection at a time.
For that purpose I'd recommend reading and supporting poets by purchasing their books: my favorite go-tos at the moment are Carol Ann Duffy's collections, 'Rapture' and 'The World's Wife', or collections from Sylvia Plath (or made post-mortem).
If you want particular structures however, I've been enjoying the read of the The Making of a Poem - It's always fun to try out a style/format/structure, and the introduction, in my opinion is a fantastic read as well.
Good luck!