By default WordPress generally uses whatever your page or post title is as the SEO title. Without it being specifically declared as a meta title in the code, though, there’s no guarantee Google or other search engines will display it that way in search results. (SEO title and meta title are the same thing.)
But if you’re looking for a specific place to edit it separately, you’ll need an SEO plugin. That will give you much more control over how your WordPress site displays information to search engines.
(For style, keyword, and length reasons there are definitely cases where you’ll want your SEO title to be different than the reader-facing title on your pages or posts.)
Yoast is probably the best known SEO plugin, but there are other more lightweight alternatives like The SEO Framework, which is one I use frequently.
Generally once you have an SEO plugin installed you can edit the SEO title on the page/post edit screen underneath the main content area. It will look something like this:
As you can see above, often plugins will give you guidance on the optimal SEO title length, and the same for the meta description.
More about page optimization here: