Blogger does not have a direct "reset all settings" option, but you can manually restore default settings by following these steps:

1. Revert Template to Default:

   • Go to Theme > Customize > Click Reset to default.
   • Alternatively, use a default theme from the Theme Gallery.

2. Restore Default Widgets:

   • Go to Layout.
   • Remove all custom widgets and use the default widget setup by selecting a new theme.

3. Reset Blog Content (if needed):

   • Delete all blog posts or pages you want to reset.
   • This can be done under Posts or Pages.

4. Update Settings to Default:

   • Navigate to Settings and manually adjust options such as:
     • Title/Description: Update with new or default content.
     • Privacy: Ensure the blog is set to Visible to search engines.
     • Permissions: Remove added authors or adjust privacy settings.
     • Custom Domain: Remove it if added, reverting to the .blogspot.com URL.

5. Delete and Recreate the Blog (last resort):

• Go to Settings > Remove your blog > Confirm deletion.
• You can create a new blog with the same title or theme.