Logging is very important, I highly recommend you enable audit logs for SharePoint Online, OneDrive, and Azure AD. Be proactive and get these enabled ASAP before you run into a situation where you need them only to discover they were never enabled. Taking things to the next level you can collect O365 management events from the following applications through the Office 365 Management Activity API. In this first part of the series we will enable auditing for SharePoint, OneDrive, and Azure AD.
Enable Auditing for SharePoint, OneDrive, and Azure AD