Mirror your interviewer's personality. If they joke around, you joke around (professionally of course). If they're super serious, you are super serious. They only hire people they like, doesn't matter how successful they are.
Research the company, make sure you know what they do and what you can bring to the table. They are looking to skew their audience younger, so speak to that.
Look up generic questions and think of answers. "Why do you want to work here?" "Think of a time where you had to overcome an obstacle"
Help answer questions real people are asking about your company. Your answers will be 100% anonymous.
The person asking the question will be notified of your answer, and it will be posted publicly. Your identity will be kept private