You would need to copy the entire local database to the online area. That means that both areas should have the same plugins and themes installed. You would also need to copy all media files from local to online. Lots of works.
There are plugins that will ‘clone’ a local database (and content and media files), allowing that ‘clone’ to be ‘imported’ into the live database. Note that all will totally replace the online database with the local version, so all current content on the online version will be lost.