If i was to get vonage, would my whole house number change or will i have my own separate number?

That is your choice. Vonage will give you a new phone number when you create your account. That phone number is different and separate from your existing PSTN telephone number. However, if you did want to disconnect your current PSTN phone number and have it tied to your Vonage account VoIP service, you would need to ask Vonage to "Port" your PSTN phone number to your Vonage account. This is known as LNP - Local Number Portability. This would have to be arranged with Vonage "prior" to disconnecting your existing PSTN phone number. The LNP process can take anywhere from 2 - 8 weeks to have your existing phone number ported to your new service provider (Vonage). LNP is only initiated upon your personal request, prior to switching services, and you are charged a fee to have your number ported to the new service provider. Otherwise, if you don't want your existing phone number ported, Vonage just simply issues you a new phone number for your area code.

When I ordered service from Vonage I told them to let me keep same number that I already have with AT&T. It took about 8 days for service to begin with the same number. Glad to get rid of AT&T with their shady ways.