timately change of name will take place after first initiation. In the meantime there is no harm in calling them by some suitable good names.
Speaking or anything all depends on practice and study. I remember when I was first called for speaking by one of my senior Godbrothers. I felt very much hesitating because I was not practiced to speak. Later on by speaking and hearing or reading I got experience and now we can speak 45 minutes, 50 minutes or one hour at a stretch. So you have to read our books very nicely and gather thoughts, then you can speak for hours without any difficulty. It requires practice. So read your books carefully, especially Nectar of Devotion now published, and practice speaking. It will be alright.