There are a lot of synonyms for the phrase "queue up" that you can use to add some variation to your vocabulary. Some of the most common ones include "line up", "stand in line", "wait in line", "form a line", "get in line", "stand by", "queue", "wait your turn", and "line". All of these phrases can be used interchangeably with "queue up" to describe the act of waiting in a line or formation. Using synonyms such as these can help to keep your writing more interesting and varied, instead of relying on the same few words over and over again.