The UDB rearranges these two verses into a verse bridge in order to make it easier to shorten the sentences. (See: [[rc://en/ta/man/translate/translate-versebridge]])
The phrase "the city of David" was a name for Bethlehem that tells why Bethlehem was important. Although it was a small town, King David was born there, and there was a prophecy that the Messiah would be born there. AT: "to Bethlehem, the city of King David" or "to Bethlehem, the town where King David was born" (See: [[rc://en/ta/man/translate/figs-explicit]])
This means to report to the officials there so they could include him in the count. Use a term for an official government count if possible.
# along with Mary
Mary traveled with Joseph from Nazareth. It is likely that women were also taxed, so Mary would have needed to travel and be registered as well. (See: [[rc://en/ta/man/translate/writing-participants]])
"his fiancee" or "who was promised to him." An engaged couple was considered legally married, but there would not have been physical intimacy between them.