DbVisualizer is normally launched using the provided executables that are created during the installation. The following is needed only when the recommended launch method is not suitable.
In the installation directory for DbVisualizer there are script files suitable for the OS you are using. These are dbvisgui.sh and dbvisgui.bat for the DbVisualizer GUI and dbviscmd.sh and dbviscmd.bat for the command line interface. Browse these scripts how to launch DbVisualizer manually.
Please see the Users Guide for information about where the scripts are located and the command line options available: