adding files to page

[Gregory Takata]

How do I add a file to a page and make it so that if someone access that file, that file becomes locked for other people to access it

[Jack Brickey]

There isn't a way to lock files inherently within Confluence. Confluence is not a documentation management application. If you wanted to do something like this, as an example, you could have links to files that are stored/managed by a documentation management solution, for example SharePoint.