How to soft reset Ubuntu? [closed]

You have configuration at the system level, that can only be changed by users with root permissions.

Then you have per user configuration. That configuration resides in the user's home directory under hidden folders and files, i.e., of which the name starts with a .dot.

Reset user configuration

As a beginning user, you may not have fundamentally changed system wide configuration. It therefore is sufficient to reset your account, or parts of it.

• To reset every setting related to the standard Ubuntu desktop, you can use the command dconf reset -f /org/gnome/.
• You can also more thoroughly reset your entire Ubuntu account.

Reset entire system

• Reinstall the operating system, erasing the previous install.

Changes at the system level are not as such logged. There is therefore no way to automatically roll back in a default Ubuntu install - you have to know what you did and undo it yourself. To have a fully pristine system, a reinstall is the only option. That, however, typically does not take more than an hour.