Example data source for educaional use
The description of the needed data is quite general, but I have found this dataset that describes sales during Black Friday; it is possible to identify products bought by the same customer using customer_id column. 

Also, this dataset describes transactions from a bakery. The products that were bought in the same transaction (and so by the same customer) are identifiable as they share the same #Transaction value.

Generally below are 2 sources where someone can find free datasets that can be used for training/ educational purposes:


Kaggle: https://www.kaggle.com/datasets (both datasets that I suggested were found here)
EU Open Data Portal: https://data.europa.eu/euodp/en/data