What do you mean by “hook my cell phone to it...?” Are you using the Sonos App?

I’m trying to connect by Bluetooth to my phone’s library play list but it’s not allowing just asking for the owner to sign out and in to proceed yet will play Spotify 

Unfortunately the Arc is not Bluetooth capable. The Arc Ultra which is the upgrade to the Arc has Bluetooth capability.

Okay well that makes sense could it be air dropped to it? as my son is able to use his I phone but he says he airdrops it to the speaker. I thought that would be the same as Bluetooth 

Yes. You can send music to the Arc via AirPlay2. The previous version of AirPlay may or may not work .

For the record AirPlay (all versions) are a development by Apple. Bluetooth (BT) is a universal code available to all manufacturers that choose to add BT capability to their devices. BT, AirPlay and WiFi are all different (distinctive) means of sending audio. 

Thank you