In order to have structure to work with, I measured key dimensions of the margins in which the content sits in. This is important as the brief says to design in the style of creative review. After measuring the front cover, it was clear there was a 7mm gap all the way around apart from the bottom, which had a 9mm gap.
I also measured the size of the whole document in order to get the right dimensions when initially setting up the document.
After getting the correct dimensions, I implemented this into indesign, where I was able to change the height and width of the document, and change the margins to what I had already measured.