Your site works right away on a temporary address, shown under Websites in your account. To use your own domain, open your site under Websites: Connect your domain lists the DNS records to create wherever you manage your domain's DNS (usually the company where you registered it):
- An A record for @ pointing to your site's IP address
- An A record for www pointing to the same IP address
- Optionally, AAAA records for @ and www pointing to your site's IPv6 address
Remove any other A or AAAA records for @ and www: they would send some visitors to your previous host and stop your free SSL certificate from being issued.
Then press Check connection. It shows each record as the internet sees it, and what to fix. DNS changes usually take effect within a few hours, but can take up to 72 hours (see "Why isn't my domain working yet?").
Go live
Once your domain points to your site, request its free SSL certificate under Security & HTTPS on the same page; it usually arrives within 30 minutes. Then press Go live: WordPress switches from the temporary address to your domain, so your pages, links, search engines and the login page all use it. If something doesn't look right, you can switch back to the temporary address for 24 hours.