Zenphoto is dependent on which theme being used. Each theme has different functionality built in (those are listed to our best knowledge on the themes section). As long as you are satisfied with what the theme chosen offers it does work out of the box. The themes are more or less meant as a starting point as no theme can be right for anyone anyway. If you need extra functionality you have to do some work yourself. This applies to all CMS out there in one way or the other.
If you wish to change things it is not avoidable to know some basics about web techniques like HTML, CSS and a bit PHP and occasionally JS (jQuery). Teaching these is of course out of scope of this forum (as mentioned onthe forum rules).
If you have this knowledge you can learn the basics of Zenphoto theming on the theming tutorial and the user guide. Again, the more special things you want to do the more you need to get into it.