Does it matter if I just edit the default demo theme for my first OctoberCMS website ?
I mean … will an update to the OctoberCMS core or demo theme overwrite my modifications to the demo theme ?
I am hoping to use the demo theme as the template to the first site before I get comfortable with the theme structure.
I don’t think it will, the theme come only when installing. But you can also duplicate it from the backend → frontend theme or just duplicate that entire folder and edit the theme.yaml just to be safe.
Themes are not usually overwritten by the system unless they are installed using composer. In all other cases, an immediate copy is produced for customization.
If you require a theme that updates, it is recommended to install it via composer, then create a child theme that references it, which, including a .themelock file to hide and prevent changes to the parent theme which may be lost during an update.
More information can be found here: