There are five stanzas in Keat's poem:
Stanza 1: The speaker is looking at an old Grecian urn thinking that the urn is able to better tell a story than a poem is. The speaker questions what the tale might be about in the string of rhetorical questions.
Stanza 2: The speaker sees a song being played and a pair of young lovers beneath a tree who are about to kiss. The speaker comments on the everlasting nature of beauty and youth frozen in the image.
Stanza 3: The speaker comments on the lovers' happiness and passion that revolves around the tree.
Stanza 4: A heifer is being lead to a sacrifice and a quiet town is set near the shore.
Stanza 5: The speaker comments on the everlasting nature of time and beauty frozen on the urn that is wasted in actual life.