There are a lot of plugins for WordPress but some are far better than others.
Meta Tags Inserter is a GNU meta tag tool that help a person improve the overall quality of a site. This tool can handle a wide range of services such as Google, Bing and Yandex. There is a custom area for situations where there is no preset box. It also provides a site description and author information for Twitter etc.
Automatic Upload Images is a handy tool that saves a local copy of any images that are cut and pasted into a post. The advantage is that WordPress has varying image sizes for various purposes. The feature image is used in lists of posts while related posts are using small thumbnails so a local image can be processed while a hotlink is useless.
Contextual Related Posts is fairly flexible and it can be adjusted to fit the theme in use. By default the related posts are near the bottom of the article.
Age Verification is handy to cover for a mature content site.
Many other plugins are used for various purposes and each site has its own needs.