1) The old website is likely cached in your web browser and is common with any DNS changes.Visit your website then hold “ctrl” on your keyboard and hit F5.
That will do a hard refresh, go out the the internet to download the latest files and you should be good-to-go.
2) Firewall or Anti-Virus software – If you are getting an error or something that says it is unable to connect, a firewall might be blocking it. To test, you can try to access your site out of the office or on your phone (if you are not connected to wifi) to eliminate this as the culprit.
3) DNS – When domain settings are changed it (such as launching a website, changing email providers, etc) can take up to 48 hours to propagate those settings across the internet so that everyone can find them. The solution for it is to wait a day or two.