I need to pair both an alexa and a phone to my arduino project. Do I need to have two different bluetooth modules?
Bluetooth is normally considered a single entity device.
You haven't really supplied any useful information about the particular board or application or code etc. (you are in the 101 board specific section)
BT tends to accept one connection at a time but with a better wireless device ESP based you could probably do what you need (still a guess).