Just starting out. Which business opportunity should I go with?

WHatever you choose, just realize that it will take work. I think you have to look at your own interests to truly figure out what interests you and ultimately what business to do. Do you want to provide a service, create a product or just be a source for information.
I would suggest that you write out a list of 5 passions, 5 problems and 5 fears that you have. After you have that list, research them and see if there are others searching for information in what you listed. You want to make sure you have a market to sell to.

Then go from there.