Langston Hughes's poem "Mother to Son" lacks a distinct setting, but it's clear that the what the speaker is doing during the poem is talking to her son. There is a sense that this is happening at a casual place—I see her on a big chair in a living room talking to her son on a couch, but that's just my perspective—but there is no definite place. However, through the title and the informal opening line that addresses her son directly, "Well, son, I'll tell you..." it's clear that the speaker is in a comfortable place.
However, throughout the poem, there is a sense of place when the speaker is talking about where she came from. She lived in poverty as life's had "tacks in it, / And splinters, / And boards torn up, / And places with no carpet on the floor— / Bare."
Both the setting gathered from the first line and the place the speaker describes helps generate meaning in this poem. Both things reveal that this poem is a passing of knowledge and a call for this mother's son to thrive in the world because if she could make it with no "crystal stair," so can he.