Here are a few resources for finding some sample data sources that I use.
Tableau Public has some great datasources that are broken down by sector: Resources | Tableau Public
Additionally there is a site called Data.World that has several free data sets hosted on it: Datasets for Analysis & Download | data.world
I also found some supply chain data on the Data.gov site that is another great source for free data sets: https://catalog.data.gov/dataset?tags=supply-chain
Hope this helps!
Cheers, Byrne, Patrick