Registering a domain name doesn't mean it will be immediately visible on the internet.
If u linked the domain to a webhosting or reseller hosting account. https://www.versio.uk/articles/156-how-do-i-link-a-domain-name-to-a-webhosting-or-reseller-hosting-account , or have provided the name servers with the order.
This may take up to 24, due to a process called propagation. Until your domain has propagated, your website and e-mail will not work.