URGENT HELP!! epub3 template?

hello,

I am looking for a working epub template with a simple TOC and some content so I cant start playing around right away. Something that I can swap content and see how it looks on a real device. This is what I want to do:

unzip, change content, re-zip it.

Later on I will deal with the more advanced stuff.

I see some examples listed but they go over many things and I end up getting lost of what I am supposed to do.

thanks.