Q: Magic Mouse 2 is not discoverable

Which version of OS are you running? it has to be OS X v10.11 or later. if it is try to pair the mouse with another Mac if the problem persists that means it's faulty and you need to exchange it.

Try pairing with another Mac, if you are still facing the same issue that means the mouse is not working.

A Magic mouse 2 should pair automatically with a Macbook Pro running Sierra.  Providing you have checked out the interference notes from Apple first,  https://support.apple.com/en-gb/HT201542   I would certainly take it to your local Genius bar and, as it is a Macbook you have, take that with you too.   You can take back any product within 14 days and receive a refund or exchange. no questions asked.  Make sure you have your receipt with you/