Formal:
* Bonjour, Brenda. (This is the most common and polite way to greet someone.)
Informal:
* Salut Brenda. (This is a more casual greeting, used with friends and family.)
* Coucou Brenda. (This is a very informal and friendly greeting, often used among close friends.)
You could also use:
* Bonjour Brenda, comment allez-vous? (Good morning Brenda, how are you?)
* Bonsoir Brenda, comment vas-tu? (Good evening Brenda, how are you?)
The best option will depend on your relationship with Brenda and the situation.