You have 3 ways to do that:
- From the Joomla administration
- From the Joomla frontend by setting up permission for a user group
- Using the Import/Export/Sync tool (.csv files)
There's only a single package for My Maps location, just install it and everything is included.
K2 location are stored in a dedicated category in My Maps location.
So you have the choice to display those location:
- Using a menu and select K2 category or Root category
- In the K2 dedicated module module
- Using the plugin editor to select K2 items