Sometimes you barely finish glancing at the side before they call you to read it in the audition. Some actors like to ask if they can have more time to sit with the script and make some choices. Others just go for it. This is a great challenge that requires the ability to rely on your instincts and impulses. If you really trust yourself, reading a script you barely know can be an exhilarating experience.
Many people freak out and get scared.
One of the keys to a successful cold audition is to forget about right and wrong. Think instead about playing. You can use your nervous energy to support you in discovering the reality of the scene right there in the audition, without having planned it all out it before. When you let yourself just get on stage, follow your impulses and react, it can result in very rich and freeing work. Instead, simply read the lines of the scene and assess the situation.