Apparently you confusion is infectious: even I cannot figure out what exactly to "tackle" first!
Are you sure you are in the right forum?
There are no limits to domains, sub-domains, email accounts, or databases for any accounts available from Vodahost. Blue Voda is a website builder "tool" and should not be confused with it having an ability to create domains or sub-domains....unless you are trying to describe the fact you have pre-created websites for domains you have not yet purchased and for sub-domains that have not yet been established????
All of the above indicates to me that you must not yet have an account with
VodaHost, for if you did, you would already be familiar with the processes of owning a domain (and how to transfer/change DNS/manage) and have not yet had the validated access to your own "real" cPanel, which you would discover to be very intuitive and which you would be able to establish add-on domains just as the Tutorials instruct.
Please review the following resources to clarify you understanding and to choose the options that make sense for you:
VodaHost Account Features Products & Prices Account Signup VodaHost Support (in case you need to ceate a ticket to address a problem) ..