Often theatre will involve workshopping and long day calls - depending on the type, there may be singing and dancing and you often have a lot of material to prepare.
Always listen in the same way you would for TV and Film regarding the scene and character and make sure you have fully prepared everything required.
You will often be acting in groups with other people, which can be frustrating, inspiring and daunting - all rolled into one. The most important thing is to focus on your own portrayal of the character, not anybody else’s. If other actors are difficult to work with, then just imagine they are doing what you need them to do to help your performance shine. However, never take over the scene and hog all of the time. A lot of these auditions are also looking at how you work with an ensemble.