Creating your own custom widgets in WordPress can be accomplished using two different options, and they are:
Video Showing Easy Option for Creating Custom Widgets in WordPress
Think of WordPress Widgets as adding new content and features to be displayed anywhere on your website and not just the sidebar. Although there are many built in widgets in WordPress, you can also search and use many Widgets Plugins freely available.
Ideally, unless your website is designed for personal blogging, you have to strongly consider as to why you would use Widgets. As long as it adds to usability of your website, then you are good to go and you can safely use it on your WordPress built site. Also consider using Plugins that get updated regularly as, most plugin developers aren’t focused on security of their plugins when coding