New or Renew Certificate

Two years ago, I allowed my host to install a Positive SSL on my website. I renewed it last year (but found the annual fee high).

Now I have successfully installed a positive SSL on another site and want to eliminate my host supplied SSL and instal my own.

I have purchased a Positive SSL certificate but have not yet verified details.

I find that the certificate that the host installed on www.teambuick.com is probably valid until 2021?

When I proceed with my details, am I renewing a certificate for teambuick, or am I purchasing a new one, because I have never purchased one for this site?

I expect a new certificate will invalidate any time on the host’s certificate, while a renewal would start on the expiry of the hosts certificate and leave me obligated to pay for a couple of more years.

Thanks