Answer:
1. The speaker in the poem is an anxious 14-year-old boy who has challenges with his leg.
This is evidenced by lines 1, 3, and 4. Sucking of the thumb is a habit that comes to the fore when some children are anxious.
2. The speaker thinks about the graduation party which takes place the next morning and is anxious to attend. The speaker is worried that he lacks the appropriate attire and no one seems to care that he is anxious.
The evidence that supports the above is found in lines 8, 9, 30,31, and 32. See lines 23 and 24 as well where he or she states that "no one is thinking about his predicament."
You can also see that each stanza ends with "my momma is in the bedroom and her doors are closed"
In order words, she seems less concerned.
3. The best way to describe the speaker is that he is a fourteen-year-old who is about to graduate from mid-school but who, just like most teenagers, is terrified about how he looks and how others might perceive him. One reason is that he wears braces and is not quite confident any clothe in his wardrobe fits the occasion.
Cheers