clearly you are also uninformed about computers (2ghz of ram and 200mhz hard drive), but that shouldn't make a big deal here.
The adapter you need is sold at your local Radio Shack. Which adapter you need depends on the device you are plugging it into. They can help you with that.
The internal speaker will be turned off, and I wouldn't expect the Apple Pro speakers to do anything either. The mac is designed around one audio output. Others are turned off.
If you do want sound to more than one location, the Radio Shack folks can get you hooked up with splitters or amplified distributors, etc...