Hi. First ensure you have the correct date and' time. The do: Settings > Apps > swipe to the 'All' tab > scroll to Google Play Store > tap Clear data > confirm... Locate Google Service Framework (Google Play Services in a similar manner > Clear Data (and Clear Cache) ...and then reboot/restart the phone. Retry the Play Store and let us know. You may need to add a New
Google Account > Remove the old one > reboot > re-add the old and remove the new.
Google Account > Remove the old one > reboot > re-add the old and remove the new.