Do you "defrag" apple computers like other computers? My laptop seems to be running slow, and someone suggested I defrag it to get rid of "cookies" that can slow it down.
No you don't, and 'defragging' has nothing to do with cookies!
How much RAM do you have, and how much free space on your hard drive?
My computer has 2 GB in its memory, but I don't know how to check to see how much of that is used.
You are confusing two different things.
RAM is memory, not hard drive space.
To see how much free space you have open any Finder window and it will tell you at the bottom of the window.
Or you can look in Disk Utility.
105.25 GB available. Is that what you are referring to?
Yes. That's plenty.
Retrieving data ...