Howl has three sections and 112 lines. These lines are very long and look almost like prose paragraphs. Ginsberg borrowed the technique of writing with long lines from Walt Whitman. When you see an indentation on the page, remember that the words are actually part of the same line. For example, line 1 in your version of the poem might look like it contains two lines, but that's only because the publisher ran out of space at the side of the page.
What's the point? Why not just call them two separate lines? Ginsberg wanted each "line" to be read in one breath. "I saw the best minds of my generation destroyed by madness, starving hysterical naked," – breath – "dragging themselves…" It's difficult to read such long lines in one breath, and it's meant to be. They are jammed with information and sentence clauses, which leaves the reader both physically and emotionally drained – kind of like the exhausted and broken-down people the poem describes. The speaker is fed-up and angry, so he doesn't have time for lots of deep breaths. We gasp for air as he flings words at us.
Howl is also a classic example of free verse. It doesn't have a regular meter. Instead, it uses a lot of different kinds of rhythmic patterns, which are repeated over and over again. Thus, section II includes many uses of the phrase "Moloch the" or "Moloch whose," which structure the general rhythm of this part of the poem. The technical term for such repeated patterns is "parallelism."
If you've ever read anything by Walt Whitman, particularly his long poem Song of Myself, you probably noticed that Ginsburg's verses are very similar. Not only do they look the same on the page, but Ginsberg uses the same bag of poetic tricks. In particular, he uses a ton of "catalog," which is a fancy word for "lists." Howl has lists nested within lists. The entire first section is a list of things that the "best minds" did, but it includes smaller lists, like the collection of places (Mexico, Rocky Mount, Tangiers, etc.) in line 64.
Also, Whitman's poems feature a lot of "anaphora," or lines that begin with the same word. So does Ginsberg. Check out how many lines in section I begin with word "who." Ginsberg was fairly obsessed with Whitman and even wrote a hilarious poem ("A Supermarket in California") about wandering around a supermarket with him, which was published in the same collection as Howl.