Everyone agrees, poetry is the language of emotions. But what are emotions? I suggest that emotions are a language; one capable of an amazing array of thoughts and judgement. Poetry, then, is a language in which both very crude and very subtle, sophisticated things can be said. Many thoughts can only be expressed in poetry. Even simple phrases like 'wine-dark sea' or 'rosy fingered dawn' are too rich to be understood scientifically or through logical anlysis.
I had no idea of how to read poetry until I was past 40. I was blocked earlier by my own pretentiousness. As a teen and I had 'taken to poetry, because it was something expected of my rather artsy crowd. My supposition that I understood poetry prevented me from learning the frame of mind suitable to reading poetry. I simply had no idea what I was missing! I can't recall what poem or author finally opened my eyes, but suddenly, there it was the kingdom of poetry. I hope that the basics, so to speak are available to you when you are still an adolescent. Whenever you learn you will be amazingly richer for the understanding. what follows is at most a few general remarks on how to go about it. There are lots of very good books on understanding poetry if you get curious, but intellectual understanding isn't that necessary or important.
my first suggestion for reading poetry is PLEASE, SLOW DOWN.The pace of modern life is too rapid, too intense, to allow for the layered meanings that are at work in poetry. Imagine a lazy summer afternoon; one where you want to pass the time - not kill it. Imagine too, a reflective, receptive state of mind - maybe akin to what the mindfulness people are talking about these days. That is, you don't want to read poetry with a highly intellectual analytical stance. Poetry i thinks works best when you can let it happen to you. My typical prose reading speed is quite fast. If I try and feel poetry -which is after all what it is all about - I absolutely cannot go at more than a mental meander or saunter. Poetry depends on intense compression; so that one has to adopt a pace that let's you experience detail. It's like getting off the interstate to get more of a feel for the local landscape.
It doesn't hurt to be aware of some of the elements that make up poetry. Of these, I believe the most important is rhythm; the beat. "It don't mean a thing if it ain't got that swing" said the Duke. While there is some poetry that is meterless, almost all poetry depends on the beat. It is part of how poetry TAKES OVER, so to speak. I think all poetry descends from the chant; the chant around the campfire. It is one source of the magic in poetry -and even the most mundane of poems must be magical. It's not necessary that you consciously identify the beat. As with all things poetic, the important issue is to Feel. it. I often have trouble catching the beat in William Carlos Williams' poems. Without the groove provided by the beat, I feel as if I'm floundering and splashing about.
The other element I'll mention here is poetry is written in poetic language (!) Lots and lots can be said about poetic language; that is is concrete, sensuous and so forth. What I want to emphasize here is that poetic expression is built on what is called figurative language. Philosophers call this emotive language. The philosopher A.J. Ayer calls this "language about nothing" (no thing). Exactly. It is a language for feelings, not things. Poetic language is made up of figures and devices. Perhaps the best known of these is metaphor; the means by which a phrase can mean more that one thing, or where several usually distinct ideas are drawn together in a single small space. The controlling idea in the song 'September Song' illustrates figurative relations, with The month standing simultaneously for the autumn of the year and the autumn of life.
But to come full circle, I think I'll close simply by suggesting to you once more that poetry is not to be read at the gallop. Poetry is dreadfully important. Poems are our canaries in the coal mine - the early signs of trouble ahead. And poetry is our guidebook to being human. The best record of human possibility is poetry. I believe we owe it to our civilization to realte to it.