Galaxy watch 4. No access to SN or model# for repair or exchange.

The 1st day I got it I brought it home turned it on just to test it out never connected it to a phone because I was going to give it to my son for Christmas well now Christmas is almost here and I'm trying to get it set up for him and it won't charge he won't power on and I can't access the serial number or the model number should I get the issue resolved