The following is a recreation of a module I created using an internal SharePoint for new hires on how to begin using their OneDrive and the department SharePoint.
It's easy! Just log in to your email (Outlook) and click on the waffle in the top left
Take a look at the two resources below that talk about the basics of OneDrive
The graphic below gives a basic overview of the two, but it boils down to: OneDrive is files for only me; SharePoint is files for everyone.