Maps are in integral part of the journalling process. Every journal has a map, nothing special needs to be done to enable mapping features.
If a journal entry has a photo with embedded location data, that location will automatically be added to the journal's map. Most photos taken with smartphones have location information embedded in the image, and so all you have to do is upload smartphone photos to your journal and the points will automatically show-up on the map.
Typically, most smartphones have the photo location feature is enabled by default, however, there may be some cases where you have to explicitly enable it.
On your journals map page, there are two tabs below the map. One called Tracks, and the other called Files:
Clicking on the View checkbox to the left of a GPS track will display it on the map.
All location information (both journal entry locations, and GPS tracks) is private (i.e. only visible by the journal owner) by default. The visibility of journal entry locations can be set individually to either public, protected, or private, as required. For more information, on what these privacy settings mean, see the help page on Security and Privacy.