Canno"t connect Arduino Uno R3 on Mac

Hi everybody :) ,

I recently bought an Arduino si it's really new to me. I have a problem when I try to connect the board on my computer (I have a Mac). Actually, my computer doesn't detect it at all. There is no window popping mentioning that " a new network interface has been detected". I made some research on the internet but still I didn't find anything that could really help me (except the fact that my board is maybe just not functional). However, the green power goes on as well as an orange light blinking.

I would really appreciate if you could help me to deal with this situation ! I'm waiting for your answers :)

Thank you,

MKleit