The tutorial mainly covers the core features of the software, it doesn’t get into everything you might encounter. The formatting presets that ship with the software are samples of how the feature can be used in your own work.
To reset the presets to the factory default, delete your custom preset file. You will find this in your AppData folder:
AppData\Local\Scrivener\Scrivener\TextPresets
The “TextPresets.bin” file should be moved to the recycle bin with the software closed. Now reload the tutorial and you should see all of the options returned.
It’s not a matter of deleting so much as just changing the format to look normal, which usually easiest done by selecting another preset, such as “Body”. You may want to update “Body” to look the way you want, first. Just put the cursor anywhere in a sample paragraph, and use the Format/Formatting/Redefine Preset from Selection/ sub-menu to choose the specific preset to update with the current formatting settings.