Check out or check in files in a document library - Microsoft Support

Learn how check files, folders, and links out of your SharePoint document library, and check them back in or discard a check out.

Top questions about check out, check in, and versions - Microsoft

The basics of SharePoint check in and check out

Check Out And Check In SharePoint Files

Sharepoint Online Check in Multiple Documents - Microsoft Community

Create a document library in SharePoint - Microsoft Support

Check Out And Check In SharePoint Files

Create a document library in SharePoint - Microsoft Support

Use the Document Library web part - Microsoft Support

Create a folder in a document library - Microsoft Support