Select is one of the top agencies in Europe. Congratulations. They represent Natasha Poly, Stella Tennant, Jacquelyn Jablonski, Liu Wen, Irina Shayk and Daphne Groeneveld.
Don't think of it as an interview as they really don't care what you say or don't say. They are not judging you on your answers and there are no right or wrong answers. You will be judged on your looks and they will take a few photos to see how well you photograph. They will probably measure you and might ask to see you walk down the corridor. Anything they ask will just be small talk so don't stress about saying the wrong thing because nothing you say matters. They have models from all over the world who barely speak English so it doesn't matter what you say.
You also don't decide what type of modelling you would be best for - the agency tells you based on where they think they can book you on the most jobs. if they think you can make more money doing runway, they will book you on runway jobs. If they want you to change your hair, you change your hair. Nothing is your decision.
Always wear dark skinnies, a tight white t-shirt or vest top and black heels to any agency. Pull your hair back from your face and go so it looks like you aren't wearing makeup
The most important thing you can pay attention to is to be confident and pay attention to your posture. Confidence is the one thing a model needs so have a firm handshake and look people in the eye when you speak to them, don't look at the floor. Also stand up straight and don't slouch. You'd be surprised how many models are rejected because of poor posture.