So the Gutenberg editor can be very interesting to use and very user friendly. If you are use to using other editors or layout systems then sometimes it is a good idea to disable it in the child theme. All you have to do is add the following code to your functions.php file.
If you are using 4.1 or newer of Gutenberg then this is the following code.
If the version of Gutenberg that is installed is older than 4.1 then you need to use the following filter.