A bicycle made for who?

Now I understand the basic concept of the bicycle, it's simple. Two wheels; the back wheel attached to a chain, which is attached to peddles that a person powers using their legs and the front wheel can be directed using handlebars. You sit on a seat that supports you whilst allowing the legs to move appropriately and it is all held together by a metal frame. It is clear that some of the challenges will require this ingenious contraption. So I decided to take advantage of the January sales and get one on the cheap.

My Internet research has just introduced me to a world full of words that look familiar but mean nothing: carbon frames, aluminium frames, straight frames, angled frames, forks, groupsets, cleats. And I'm not sure if I was looking at saddles or some sort of ancient operatic tool for creating castrati . Bicycles are built for on-road, off-road, racing, time-trialling, touring, stunts, commuting or a combination of these. And the price range seems to have no boundaries. I am going to need an expert, either that or I find the London to Brighton on a pennyfarthing challenge.