inner page in single.php

I want to make a gallery website but each event has different intro page, Could you please help me what`s the concept of designing the page in wordpress?

more detail: I have a main page which has the list of exhibitions and when we click to each exhibition we go to a page with info and gallery link and poster of that gallery. and when user click gallery will be directed to gallery of that event and when user clicks info will be directed to info of that gallery. it seems that we have a single.php for (poster+ info link + gallery link) and we have 2 inner single.php for gallery and info which is linked with intro page(which is different by another exhibition)

I would be appreciate to hear your strategy…