If you want to choose the blog preview image that Facebook uses when posting a link to a page or post in wordpress you need to install the YOAST SEO plugin.
Scroll down to where it says “social” and then choose the image and preview text you want users to see when you post this page on social media.
If you want to avoid the delay in Facebook where you have to wait a few days before Facebook sees the change then head on over to https://developers.facebook.com/tools/debug/ and paste in your URL.
You will then see a “scrape again” button. Click that and after a few mins, refresh your Facebook and try sharing the link again. It will now show the recent changes you made to your OG social preview.
