How to do this in css

Hello everyone
I could not search this a lot since i have no idea how it could be named this what i want to do.

Basically its something probably done in javascript but i wish to make it from scratch by myself, and in css.

What i am having difficulties copying is the changing images from this website: http://www.websitetemplatesonline.com/free-template/handy-man-free-theme.html

I was thinking of using some hide attributes and making them appear one after another...but not sure how to do that, especially about the buttons.

P.S. I downloaded it from their website but have no idee how to use it, especially when it makes random events as....super small text and random code appearing in middle of paragraph. And no, i didnt delete or add from mistake code.
And also im using DreamWeaver but mostly for things i dont know how to do or to help me find the tags i used and so on. Or to visually resize different photos for now.

Can anyone help me with an example or even show me something related that could help?
Thank you.