You need to log in and check your PrestaShop's admin panel. There is a bell icon in top right corner with a number showing new notifications, including new order notifications. Click the bell icon to see more details.
By default PrestaShop does not notify the admin about new orders by email. If you'd like to receive an email notification, you might be interested in my Bcc All Email to Admin -addon module, which sends a blind carbon copy (Bcc:) of every outgoing customer email to store administration team:
https://addons.prestashop.com/en/emails-notifications/42587-bcc-all-email-to-admin.html