Content in a WordPress site can be put in a "post" or a "page." Why two types of places for content? Posts are intended for content that will be sorted by date, commonly in reverse-chronological order so that the newest content is at the top, such as in a blog. WordPress has features that make setting up this sort of system for your content very quick and easy, with your recent blog posts on the front page of your site by default.
Pages are intended for content that is not chronological in nature, such as a Contact page or an About page. Many WordPress sites are set up to use Pages and no Posts at all, and use both a static front page as a place for site viewers to land, and a Menu or Menus to guide viewers to other pages.
Many sites incorporate both a blog section with posts, and a set of pages linked to from a static front page and a menu. See Appearance and Navigation for more information on the best ways to set up a menu.
When you create your WordPress site, take the time to think about whether you want your content to display chronologically or not, and this will guide you in what mixture of posts and pages you may need, and in particular, whether you should set up a static front page. If you are using WordPress on a shared site as part of a class project, check with assignment instructions or your instructor for instructions on whether you should be putting your content into posts or pages.
You can learn more about Posts and Pages on the WordPress support page about Pages.
Here are a few things you should know about writing your post:
If you are working on a course project, your instructor may have a specific Category where they ask you to place your post. Categories control where your post will show up on the final site. Set the correct category by looking in the Settings panel on the right-hand side of the editing window.
When you have added any additional needed content to your contribution, click Publish to complete your post. You can always come back to the "All Posts" view in your Dashboard if you need to make changes later.
You may want to become familiar with available blocks.
For many sites on Commons, it is appropriate to switch from a blog-like style (where the posts on the site are displayed on the front page in a chronological order) to a static front page. In order to do this, follow these instructions on Wordpress.org: Creating a Static Front page
Categories and tags are ways WordPress provides for categorizing posts. Categories have a hierarchy: for instance, you could define a parent category Fruits and child categories Apples and Bananas.
Tags are another way of labeling posts, and you could likewise set up, for example, tags for Fruits, Apples, and Bananas, but tags have no way to indicate that Apples or Bananas are types of Fruits.