1. "Ah, distinctly I remember it was in the bleak December;
And each separate dying ember wrought its ghost upon the floor."
- this is a trochee, which means that the first syllable is stressed, and then followed by an unstressed syllable: ah (stressed) dis- (unstressed) tinct- (stressed) -ly (unstressed), etc.
2. The other poem is written in free verse, which means that it doesn't follow any rules when it comes to rhymes, stanzas, verses, etc.