Yes, you are required to pass the B1 exam with high marks before arriving in Germany. You will also be required to study as much B2 course as possible prior to arriving in order to shorten the time for you to take your B2 exam once you are in Germany. Once you pass your B2 (and as soon as you have completed your Qualification Recognition course and exam), you will become a Registered Nurse, which earns more than a Nurse Assistant, and you will be able to stay in Germany long-term.