All export reports can be found under the exports tab on the left as shown in the screenshot below. The main reports you would need to worry about are All customers, All Purchases, Product Distribution and enhanced product distribution.
Both All Customers and all purchases will prompt you to submit a request to download a CSV file which will contan all information on purchases and customer details.
However for more detailed reports you would need to go to either product distribution or enhanced product distribution. for this example we will got to enhanced product distribution. Here we can see that it provides options that allow you to select the product group, product types, the start and end date, or go by a range of other options like financial year, etc. You can either view the information on the page after hitting submit or select output as csv to download the information.