OH one thing I wanted to mention.
Pain is always a sign of trouble.
If your pain is the latter, it could be your body telling you that somethings being damaged. Many musicians have come to grief by ignoring these pains for too long. The first step is good technique and posture, and it is almost always the cure. This may be hard if your arms isn't used to holding a bass, but it is important. Don't clench the neck of the bass with your hand, but rather use your whole arm to pull the string onto the neck.