1. "Привет" and "ты" regard to an informal relation. "Вас" regards to a formal relation. So you should be consistent. If you use "вы" you must say "Добрый день!" or "Здравствуйте", not "Привет". 2. In Russian they asking "как у тебя дела" only in case when you realy want to know how the things go. So friends could ask each other about it, but not the persons just met in the first time. They rather say "Приятно познакомиться" (Nice to meet you). 3. The response should be little differ from the opening phrase. Otherwise it sounds a bit like a teaser. So you should use: ---Меня зовут Анна ===А меня - Сергей. or ===Cергей. 4. Calling themself by just a first name matches only for youth. The old people or people with formal status will call themself by FirstName+Father's name. For ex, Меня зовут Анна Александровна. (If her father is Alexander).