Set Site's Featured Image on Facebook

I’m trying to change the image that shows in the thumbnail when I share my main page on Facebook. It currently shows a picture of Indian food from one of my posts and I don’t really want that photo as it doesn’t reflect my site’s mood and feel. I can’t find any solution that I can understand about setting a home page featured image. I know nothing about PHP so I was hoping there was a plugin I could use that won’t bulk up my site’s loading time. I know I need to change the meta information but don’t know how.

https://www.livelaughandplay.com