[Theme photography] by themegoods not showing picture by url

Theme Name: Photography

Version: 2.2

by ThemeGoods
https://themeforest.net/user/ThemeGoods

Hello

Please help me i’ve been searching for hours ??

Normally with my old free them from wordpress i saw I picture on the left if i send somebody the link of my website and by the picture on the right side there is always the link

when i now type my link on facebook https://www.janedewaard.nl or on my phone i get nothing (see screen capture 1)

But i Go to https://janedewaard.nl/category/photoshop/ i do get what i what (i think the theme takes a random picture but see capture 2)
and thats what i want if i link my website to https://www.Janedewaard.nl
I want to see a picture at my url

my theme is now with a static homepage
but when i changed it to latest post i still had no picture with my url

I dont know how to fixx this. Can someone please help me?

and please tell me in child language as in step bij step (example go to settings, than go to guestbook, create new title of your guestbook etc etc) as you can see my english is not so good and my knowledge of wordpress is even more bad!

Thanks you

capture 1

capture 2