This is the 2565th most frequent Russian word.
собрались
"Собрались" means "gathered" or "assembled."
In this sentence, 'собрались' is used in the sense of 'came together' or 'assembled' to indicate people meeting at a location.
Мы собрались в парке, чтобы отпраздновать праздник.
We gathered in the park to celebrate the holiday.
Here, 'собрались' conveys the idea of a group convening for a specific purpose, which is to discuss something.
Он сказал, что они собрались обсудить важную тему.
He said they gathered to discuss an important issue.
In this example, 'собралась' is used reflexively to mean 'prepared oneself' or 'got ready' for an activity, in this case, traveling.