Have you noticed that the speaker of this poem thinks this young man is good looking? Like, really good looking? He manages to cram the word "beauty" in four times in fourteen lines. We think there might be a couple of reasons for this. On the one hand, maybe this young man is so vain that the only way to get him to do anything is to tell him he's good looking. On the other hand, maybe the speaker of this poem has a thing for this young man. In fact, the sonnets are often used as evidence to suggest that Shakespeare himself was attracted to men. We don't think you can prove that using these poems, but keep an eye out for hints of possible attraction between the writer and his subject.
While it pretends to be an argument for having kids, Sonnet 2 is actually a love poem from the speaker to the young man. The speaker uses the excuse of giving him advice to repeatedly and extravagantly describe the young man's beauty.