Convert a Template to a Website

I am building myself a wordpress website - [login to view URL] I have purchased a theme and am using the provided portfolio gallery. I would like to edit the animation when the mouse is hovered over the image, I would like it to pop like the in the link here - [login to view URL] Must know how to edit Child Theme files to not be effected by Theme updates. If this is something that you can do, please send me a personalized response. Thank you.