WordPress 5.0, also called “Bebo”, has been released recently. I think there never has been an update before that had to deal with so much criticism. Many people were alarmed, because the release date on December 6th felt a little rushed, with only a few days of notice beforehand. Also, the new editor, Gutenberg, still has a lot of Accessibility issues, although the WordPress Accessibility team and the Gutenberg developer team worked hard to eliminate as many problems as possible.
From my personal view as a web developer, I would advise against updating to WordPress 5.0 too quickly. I would suggest waiting at least until version 5.0.1 is out. Usually, after a release of a major update there will be bugfixes coming up in a short amount of time and the bigger problems will be eliminated shortly after the initial major release.
You don’t have to worry that your WordPress installation will update automatically to 5.0, since the auto-updates only work for minor releases (unless you have altered the configuration yourself).
WordPress 5.0 is not a security update, and the previous version 4.9.8 should continue to receive further security updates if needed, so there’s no big reason to update right away. If you’re using Wordfence, you will get alerts that your WordPress version is out of date, but in this case, it’s just an information – you can read their posting on this topic here.
Also, many themes that use their own layout builders for the content of pages and posts, still have compatibility issues with the newest version of WordPress.
There is a plugin called “Classic Editor“, which will enable using themes that don’t yet support Gutenberg. It is planned to be supported until 2021.
There is no need for you to panic, and you don’t have to rush things. I would advise you to try out WordPress 5.0 and Gutenberg on a development install, where you can safely play around, test your site and get used to the new WordPress version.
I am sure that WordPress will continue to serve as an easy to use Content Management System and that 5.0 and upcoming versions will include great improvements.