Hi Krystyna,
You can convert all your HTML websites to Drupal website. For each website you will need a domain name and to host those drupal websites you will need a hosting package. We provide
Webhosting as well as domain name registration services. You can purchase the hosting package and domain name from us. You can consider one of our cPanel hosting plan to host all your Drupal websites. You can view the cPanel hosting plans and pricing details at
cPanel Hosting UK | Shared Linux PHP MySQL cPanel Hosting
Let me know if you have any more questions.