If the USB cable doesn't work from scratch, you'd try to transfer the files using the official Samsung SmartSwitch.
Method #1: USB Cable
Install SmartSwitch in your computer and make sure it is installed in your smartphone.
Then, connect the USB Cable from your smartphone to your computer and run SmartSwitch. It should detect that the phone is connected.
Now, run a complete Backup and wait until the process finishes. It could take a while, depending on the number of photos or information you have.
Once completed, you'd need to find the folder where SmartSwitch saves all the backups. A new backup folder is created each time, but inside you can find all the information that you had in your mobile, including a folder with photos!
Tip: you can use Finder and list all the files in your computer All Files, and then order by date created or added. This way you can find where the files were saved.
Method #2: Wireless Transfer
Alternatively, you may try to transfer the files wirelessly either via Wifi or Bluetooth, ES File Manager can help. However, bluetooth approach can be really slow if you have too many files to transfer.
Method #3: Using the Cloud
Another 3rd. approach could be to synchronize all your files via Dropbox and then use the Dropbox Desktop tool in your Mac to get the files saved in your Dropbox account.
Lastly, sometimes the USB cable doesn't work because you need to enable the MTP (Media Transfer Protocol) protocol to transfer files. You'd try to use the Developer tools in your smartphone to get this working. But try first to use the previous listed methods before trying this one, please.