You should always update WordPress to the latest version. When a new version of WordPress is available you will receive an update message in your WordPress Admin Screens.
Currently, there is a plugin that takes care of automatically backing up your site once a week. However, before you update to the latest version, it’s a good idea to manually back up your website. This means if there are any issues you can restore your website. Complete instructions to make a backup can be found in the WordPress Backups section of the documentation.
Updating WordPress with a Single Click
You can launch the update by clicking the link in the new version banner (if it’s there)(Fig. 1) or by going to the Dashboard > Updates screen. Once you are on the “Update WordPress” page, click the button “Update Now” (Fig. 2) to start the process off. You shouldn’t need to do anything else and, once it’s finished, you will be up-to-date.