Iād like to change the permissions for the /var/www/nextcloud
folder with chown -R www-data:www-data /var/www/nextcloud
so i can edit things like upload-restrictions, etc.
What are you trying to do? Increase max upload size?
You really should follow the āSetting Strong Directory Permissionsā outlined in the documentation for production deployments. However, short deviations from this (for updates, changes) should be fine, but they do open security holes, namely if the webserver gets compromised.
What you are trying to adjust are settings not folder permission which is what you try to do. The settings for your Skeleton-folder is in your config.php file and the max upload can be increase via the .htaccess file in your root directory.