Possible meanings are 1) "song people sang while going up to Jerusalem for a celebration" or 2) "song people sang while going up the steps into the temple" or 3) "song whose words are like steps." See how you translated this in [Psalms 120:1](../120/001.md)
The writer briefly stops speaking to his audience and speaks directly to the city of Jerusalem. Jerusalem is spoken to as if it was a person who could hear the writer. (See: [[rc://en/ta/man/translate/figs-apostrophe]] and [[rc://en/ta/man/translate/figs-personification]])