Featured Image Hover Effect

Hi,

I tried to look through the forum to see if someone already asked this, apologies if I missed an answer.

I’m trying to simply take the hover effect on feature images, like on a blog post when the featured image enlarges when the mouse goes over it.

I tried to create some custom CSS but i must be missing something or be completely off lol.

If anyone has the CSS that would be amazing!!!
Thank you in advance!
Tori