"Word choice" refers to the words a poet chooses to use. Word choice is extremely important in poetry, since the poem is such a compact form. Every word counts. Sometimes poets choose words for the way they sound; sometimes for their connotations. When you look at word choice, note whether the poet used a specific or general word: did he, for example, choose to say "dahlias" rather than "flowers"? Why? Note whether he used a concrete or abstract word: did he, for example, refer to a "Medal of Honor," rather than "bravery"? Why?
For example, look at Sipho Sepamla's "Words, Words, Words," on page 729. This is a poem about word choice: "We don't speak of tribal wars anymore / we say simple faction fights." Think about the words people use to talk about events: what connotations does the word "tribal" have that "faction" does not? When you think of a "tribe," what images come to mind? What images come to mind when you think of a "faction"? If you want to be taken seriously in the world, then, do you want to be considered part of a tribe or part of a faction?
The same can be asked of the difference between "tribes" and "nations: "there are no tribes around here / only nations." Which is taken more seriously at the United Nations, for example: a tribe or a nation? Which will have more power? "it makes sense you see / 'cause from there / one moves to multinational / it makes sense you get me / 'cause from there / one gets one's homeland..."
Sepamla's poem is about the power of words: what one chooses to call oneself can actually alter reality.
"Word order" simply refers to the order in which words are arranged in the poem. Does the poet use a conventional sentence structure, or does he invert the order of words so that the subject comes after the verb, for example? Why would he do that? How would the poem's meaning or impact be different if the words were phrased differently?
For example, look at Gwendolyn Brooks's "We Real Cool," on page 746. The first line, "We real cool," has no verb. How does this affect your impression of the speaker?
Each sentence is three words long. Why?
Each line ends with "We"--except the last one. Why?
And a question about voice: why is the speaker "we"? Why not an individual--one of the group, perhaps?
Brooks's poem is short, and seems simple; but Brooks has obviously spent time and effort to create this impression, so that the message will be even more powerful.