Being a rolling-release distribution based on Manjaro stable branch - Mabox gets updates approximately every 2 to 4 weeks.
By default pamac-applet is running in system tray, so you will be informed about any available updates.
Conky will also show available updates.
Before performing an update, it is a good idea to have a look at the official announcement on the Manjaro forum.
You can use Pamac - graphical package manager to perform the update or just run it in a terminal: