This video covers adding pages and posts to WordPress. It covers adding a blog to the site and making it different from the home page, setting your home page and adding an image and simple gallery. Please note that it does not deal with page builders. Also, there might be some slight differences with a different theme but the concept is pretty universal.
A note on page builders, I am not a big fan and find page builder hard to use for beginners. When I find a page builder that I really love I will post a video on that topic.
This video covers adding some basic security to your WordPress website. this plugin allows for changes to the htaccess file which will help protect against hackers. This is not 100% fool proof and I recommend backup your site and keeping plugins, themes and software updated.
Adding users to your WordPress site can let others help you manage content without giving out your password. I recommend that you have more than one user with admin access to any WordPress website. This will protect you in the event you lose access are unable to access the email address with the password reset.
Adding and editing the sidebar or widget area of a wordpress website is covered in this video the actions are the same, however different themes have options for different for widget areas some have footer areas, and others have different options for sidebars. See the widget area of your theme to determine what areas you can edit with through the widget area.