After you have saved the page, click on the Page Properties button.
On the following screen you will see the page full URL and the Page ID.
To navigate to your second page, all you need to do is link to it.
For an example, here is a POST form redirect from Page1 > Page2 on a simple form page that redirects user to a Thank You page.
Though if you say you see two pages with the same URL and are navigated to the main one, it sounds like you created content for the Cloud Page.
To double check open up Cloud Page studio > open up a Collection.
If you don't have your Cloud Pages here, then you probably created it as a piece of additional content, rather than a second page.
Navigate from the Collection to the Page Properties, if you see your page 'collection' over there then it's a piece of content and doesn't have it's own unique URL as it's read as a part of the initial Cloud Page.
If you click on Create button over there, it will offer you only the option to create Content and nothing else (like Code Resource, Microsite, MobilePush page etc)
Here's the options you see when you actually want to create a landing page..
Here's the option you see when creating content for the landing page..