If you want to use Google services (such as Gmail, Google Play and Picasa), you need to activate a Google account on your tablet. It's easy, but remember you need to set up your tablet for internet before you can use this function.
Tap the time in the bottom right corner of the display.
Tap Add account.
Tap Email and key in the username for your Google account.
Tap Password and key in the password for your Google account.
Tap Done. Follow the instructions on the display to select settings for your Google account.