Keeping WordPress, your theme and plugins up to date is the single most important thing for your site's security. This order keeps the risk low.
Before updating
- Back up your files and database (from the Backup section in cPanel or DirectAdmin, or with a backup plugin).
- If you run a store, pick a quiet time.
Suggested order
- Update plugins first, one at a time, opening the site after each.
- Then update the theme.
- Finally update WordPress itself.
If the site breaks
- Deactivate the last plugin you updated; if you cannot reach the dashboard, rename its folder in
wp-content/pluginswith your hosting's file manager. - If that does not help, restore the backup and contact support.