It’s possible to make a business out of pretty much anything. What’s key is having a passion for the subject.
A sales-based business could be anything from selling apples to zippers.
A service-based business could be anything from accountancy to zoology and wildlife conservation. or providing a middle-man service that sits between the producer and the customer.
It might be better for him to focus on what he is passionate about outside of study. A good exercise is to mind-map everything to do with that passion and see what opportunities might spring from that. People can make money from creating a website dedicated to a particular passion and finding sponsors for that. It’s essentially how Mumsnet started.
If he has a good head for numbers and is studying how economies and business works that will set him in good stead for the underlying functions of business; it will help with creating a business plan; working out where the market is and what the competition i, but these are skills that can be applied to anything.
We see how this does or, all-to-often, doesn’t work in the kinds of people who pitch up for Dragons’ Den. They arrive full of enthusiasm, with a good idea for a product or service but have poor skills in design, financial projection, how to scale up production and how to market.
It’s pretty easy to set up and run a website with e-commerce functions using drag and drop website builders such as Wix, SquareSpace, Ionos etc. An alternative is to buy in a professionally-built turnkey or bespoke system. Similarly, accounting can be done with any number of off-the-shelf systems, from Sage to smaller apps.
Unless he has a particular passion, my advice at this stage would be for him to find some part-time work, either paid or voluntary, in an area that interests him, to get a general feel for business and see where it leads.