Hi,
Good luck with your venture, but I just need to say if you "don't have a clue where to start" this is probably something you do not want to do lightly. Relying on a script/engine will in all likelihood result in the loss of bitcoins. This is not to dissuade you, just to be careful and it will be really important to figure out what is going on where in the code.
Perhaps you can find a partner to do coding while you bring capital and experience or some similar division of labor. Just be careful because there are unlikely to be "off the shelf" scripts to do this.
(As an aside, this probably does not belong in this section, perhaps in the Services section).
This, ten times.
If you have no idea what you're doing, creating a Bitcoin exhcange (or any other service that handles customer money) is a big no-no. However, if you do want to go ahead, ask yourself how you would differentiate from existing services. There are already many Bitcoin exchanges with various modes of operation. What would your service offer that the others don't? And is there demand this?
