My task is to analyse a particular business sector by collecting data from it, the business sector I chose to analyse is Retail. The type of analysis I'm conducting is 'Trends over time'.
And the Data I need to collect is descriptive data and numerical data.

I'm very much new at this kind of stuff, I don't know what to look for here.

In terms of trends over time regarding retail, what are some examples of descriptive data and numerical data?