Some of my domain registrar is Namecheap.com I always love their service, the simplicity of the operation and their customer service. They also offering low cost shared hosting service.
Lately, I also bought a VPS hosting account from VULTR, for $5 per month.
Ok let's back how we can connect a domain in Namecheap to VULTR:
Login to VULTR dashboard:
Notes the server's IP address, you will need this in the next 2 steps.
Type in the IP address from previous screen
Now login to your Namecheap dashboard and click manage for the domain you want to connect.
Add A Record fill with @ as host and your server's IP address as value, save (click green checkmark icon).
Add CNAME Record type and fill with WWW as host and your domain name as value, save ( click green checkmark icon).