To be able to manage DNS records for a domain name with no cPanel account, you can do this in just a few steps.
Update the nameservers on your existing domain to the following:
Create An Alias
You can park the domain on your account, also known as creating an alias. This enables you to control the domain. You can learn how to do this by following this help article - Creating Aliases.
Create DNS Zone
Once an alias record has been created, you can edit the DNS zone for the domain and point this to HostPresto!. To do this, please follow this help article - DNS Zones.
If you do not have any cPanel account with HostPresto!, please Contact Support with the DNS records you require and we'll set it up for you.