In WordPress, you can either write a Post or a Page. Posts are like blog entries, and by default they display in reverse date order in the main content stream of your website -- that is, newest post at the top. Pages are for things like your “About” or “Contact” page, and they live outside the stream of posts.
Pages are for content that is less time-dependent than Posts. They don't display in your main content stream, but only as a page with its own URL.
Creating a Page is much like creating a Post. Add a page Title, add the page content in the main text field, and add media and featured media as you wish.
By default, Pages use a single column template, but you can change this in the Page Attributes panel. Good options there would be Full Width, or if you want a sidebar and use the Two Column Classic template, then pick a sidebar. (Remember you can create any number of custom sidebars for use on different pages. This provides a great deal of flexibility for displaying special sidebars, for example, on certain Pages.)