Lines 1-24 Summary

Get out the microscope, because we’re going through this poem line-by-line.

Every morning, suit,
you are waiting on a chair
to be filled
by my vanity, my love,
my hope, my body.

The poem begins by addressing a suit. By writing in the second person point of view, Neruda is letting us know that this suit is his audience—interesting.
Because Neruda says the suit is waiting, and as far as we know suits don't have feelings (nor can they understand poetry), the poem takes a surreal tone.
And because it's addressed to someone, or something, that isn't necessarily able to respond, it's an apostrophe.
At least, we can assume the suit can't actually respond. Then again, the suit can't actually wait for him, either, but the speaker goes ahead and gives it these human characteristics for the purpose of the poem, so let's just roll with Neruda's use of personification, a.k.a. giving human traits to non-human things.
Though the suit is able to chill out and wait like a human, it seems to need the speaker in order to do anything else. When the speaker puts the suit on, it's suddenly filled with his vanity, hope, and love (in addition to his body).
That's when the suit really comes to life.

Still
only half awake
I leave the shower
to shrug on your sleeve,

It's worth noting here that some translations have the word "water" instead of shower.
In that case, the speaker isn't literally sleeping underwater (at least, we hope not). He's using figurative language to compare the feeling of waking up to the feeling of emerging from under the water.
Figurative language is a favorite tool of poets, Neruda included. You'll notice he uses it a few times more in this poem.
Whichever translation you use, you'll also notice that Neruda likes to keep his lines pretty short, breaking up sentences into several lines. That keeps them flowing down the page, smoothly.
This is another poetic tool, called enjambment. Check out "Form and Meter" for more details.

my legs seek
the hollow of your legs,
and thus embraced
by your untiring loyalty
I take my morning walk

The tone is almost romantic here. Neruda was famous for his love poems, after all.
But perhaps it's a more platonic relationship. The speaker emphasizes the suit's loyalty. It's like a good friend that you can always count on. A good friend that is happy to see him, the suit "embraces" the speaker's legs.
After putting on the suit, the speaker can go out and take a walk. It's important to note that he calls it his "morning" walk. That indicates that he does this walk daily. He sure is a man of routine. Maybe that's why he wears the same suit every day. It's part of his routine, which clearly is important to him (and thus, he establishes that the suit must be important to him, too).

work my way into my poetry;
from my windows I see
the things,
men, women,
events and struggles
constantly shaping me,

Hmm, how do you "work your way" into poetry? For the speaker, it seems to be a state of being that he can enter only once he's gotten ready for the day, by showering and getting dressed.
It seems like his poetry is already there, waiting for him—just like his suit.
Once he works his poetry on like a pair of pants, he can be in his poetic state of mind. And when he's in this poetic state of mind, he also notices other people.
Their lives—full of events and struggles—"shape him." They make him who he is.
So, without putting on his suit every morning, he wouldn't be able to take walks, write poems, or gain experience from the people around him.
We guess he owes his suit, big-time.

constantly confronting me,
setting my hands to the task,
opening my eyes,
creasing my lips,

All of these people, events, and experiences "confront" him. That sounds kind of negative.
Or maybe not—Neruda liked to be faced with the every day things of life (he did write a whole book of odes to everyday things like his suit, after all) because they inspired his writing.
Being confronted by these daily trials and experiences, then, was part of his poetry. So really, he's grateful for the everyday things, which make him aware. They also give him plenty to talk (and write) about.
Notice the repetition of –ing words in these lines? This adds a bit of cadence to the otherwise straightforward poem. Head to "Sound Check" for more on this poem's sounds.