Are you using the google contacts sync option in BIS, or the Google Sync app?
If the former, when you set up your gmail account on the BIS homepage
https://bis.na.blackberry.com/html?brand=vzw&locale=en you should have been prompted about whether you wanted to enable contact sync or not. If you checked the box and completed the install, all you need to do now is go to email settings on your BB, login, and you should be prompted to accept sync. Once you accept, save and close the sync will (eventually) begin. If that didn't work for you I've had to delete the account in BIS then set it up again and go through the sync acceptance. If you'll just do a backup in DM first you can restore your messages database from the backup after you're set.
Hope that helps, and Welcome to CB!