Landing pages that you code yourself in Pardot are based on something called Layout Templates, effectively just an HTML page that you code or import into Pardot.
Finally, there is one final important note. When you create any landing page in Pardot, it is hosted by default on the pardot domain. That means when you first create your landing page the URL might look something like that in the screenshot below:
The Pardot help documentation can step you and your webmaster through the process of Adding a Tracker Domain in Salesforce Pardot. You can access the setup for Domain management in Pardot > Admin > Domain Management
Once you have your tracker domain configured in Pardot, you can verify that your configuration is set up properly in Pardot:
Don't forget to make your Pardot Tracker Domain used in Pardot by setting the Action to "Set as Primary" which will be reflected in the Pardot interface as shown below:
As a next step, you might find the following educational resource guides useful: