Using Bluetooth Module to send audio to a wireless headset

Hi! I won't be delaying much and tell my problem directly.

So, my project is to create a smartwatch with ultrasonic sensors while using bluetooth to warn the user. In other words, I have a problem with regards to the part of connecting bluetooth module to a wireless headset.

I've seen a previous forum about this matter as well, yet I can't quite understand a part of it, and I am not sure where either.

I would like to have some help here: What kind of bluetooth module should I use to be able to connect to a wireless headset? I already bought HC-05 and an sd card module. Too late when I realized I bought the wrong bluetooth mod for I am a beginner. And also, I am using Arduino Uno.

Your help would be appreciated very much. Thank you.