The standard way is to install the Metatag contributed module. It lets you configure meta tags globally, per content type, and per individual piece of content through a clean admin interface.
Install it with Composer, enable the module, and configure defaults under Configuration, then Metatag. You can set up title tags, descriptions, Open Graph tags for social sharing, Twitter cards, and much more.
The module also supports token replacement, so you can pull in field values dynamically. For example, you might use the node title as the meta title and a summary field as the description. Pair Metatag with the Schema.org Metatag module to add structured data for rich snippets in search results. Together these modules give Drupal excellent SEO capabilities out of the box.