For your new website to respond to your chosen domain you will first need to to change the destination IP address for the DNS pointers that tells browsers where to look for the website.
For this example, I am using 123-Reg's control panel:
For the majority of sites you will want to create or update two records, those are:
1) The record for the base domain, i.e., virtualsamples.com
2) The record for the subdomain www. for www.virtualsamples.com.
The 1st is shown in the above example as '@', this should be of record type 'A' and use an IP as the destination. The IP address you need to use will be provided one of our support staff / project manager.
The second can be of type 'A' or 'CNAME', which is used is down to preference.
If using an 'A' record then the same IP as used previously can be used here.
If using 'CNAME' this needs to use the base domain name as the destination as shown below:
Please ensure you use only a single entry, either type A or type CNAME - NOT both, for each subdomain record (www) or this may lead to issues in the future.