Need CSS Code Help

I can’t figure out how to reference the image in Easy Testimonials Pro so that I can change the size.

I saw this in their documentation:
.wp-post-image.attachment-easy_testimonial_thumb{

I can’t get it to work with the following test:
.wp-post-image.attachment-easy_testimonial_thumb{
Height: 500px;
Width: 700px;
}

Also, is there a way to specify the image location to be on top of the quote instead of on the side?

Is there a way to reference the quotation marks to make changes to the font or color?

Is there a way to reference the line that appears in some of the images?

Thanks!