What course can I take during my 4 month holiday to equip me with skills of trading and doing business online?

There is alot of business which goes on online. I have a 4 month holiday. I wonder if I can take a course that will equip me with skills to trade and do business online. Internet will soon become big business in my country after 2 undersea fiber optic cables are complete. I want to be competitive in all that business. What sort of course should I take for those 4 months?

If i want to get a job managing an online store for a local business what certain skills would i need?

On the job board at my high school there’s a job listed to help manage an online store for a local business. I’ve never had a job like this before, but i’m pretty good with computers, and i can learn anything pretty quickly if it has to do with computers. But i was wondering what other skills i would probably need?