The basic WordPress.com plan does not allow plugin installation.
Upgrading to the WordPress.com Business or eCommerce plan allows you to install plugins from the official WordPress repository, like Yoast SEO, or upload custom plugins, like Yoast SEO Premium.
Learn more about the different WordPress platform options here.
Please know that certain code snippets, such the ones needed to implement Yoast SEO Breadcrumbs, may not work.