Both systems allow you to create websites. WordPress is originally more suitable for simple blog sites, so it is also relatively easy to quickly assemble a simple WordPress site: you create a few pages, write a few blogs and you are ready.
With Joomla you have to think about it a bit longer, but with Joomla you can also create a working site in a short time. You make a layout for your content and with the different menu item types you determine how you will show your content. Joomla has many more options and therefore a greater potential to grow your website.
Content and blogs
WordPress distinguishes between pages and blog posts. That is an essential difference compared to Joomla.
At Joomla you put all your content in one place, namely in articles. In Joomla you have more different page types to choose from by default. For example, you can create pages with one article, but also with more articles from one or more categories and set per page how they should be displayed.
Blogging is fine in Joomla: you create a category for your blogs, attach a menu item to it, set it up and from then on all your blogs will be placed on the site in the correct way.
Do you want to draw attention to your blogs? Joomla has modules with which you can show the latest or most popular articles (and therefore also blogs). You can put those modules on all pages where you want them with a simple check. With WordPress, this functionality is limited to a Most Recent Posts widget, which shows you in a fixed place on your site. With the widget itself you cannot choose which pages it should be on: it is on or off.
Create a new page
If you want to create a new page in Joomla with one text on it, you create an article with the text and link it to a menu item. In that menu item you can set a whole series of options: whether or not to show the author, whether or not to show the publication date, whether or not to show tags ... In WordPress you immediately create the page. Where you actually just write text in Joomla, you can make the page superfancy in WordPress with blocks in the Gutenberg editor. This allows you to add separate widgets to your page. After you've saved the page, decide whether you want your new page to show in the menu.
If you like the WordPress method (build single pages), you can install a Page Builder in Joomla just like in WordPress to create collection or landing pages.