Setting Gmail/Calendar notification for IOS

1. click “settings” -> go to “notifications” 

2. click “Gmail” or “Calendar” -> check “Alerts” 

-> you can set sound on/off and Badges on/off and Alerts on lock screen or notification center or banners 

Setting Google Drive notification for IOS

1. click “Drive App” ->  Menu

2. click “Notifications” -> Notifications Enabled

-> You can turn on/off for each options on notifications