OK, you are probably trying to start too fast. You really should read the Answers to frequently asked questions... But in the short form...

When you "add a placemark" GE captures a lot of parameters about your current place and view. (Lat, Long etc). Then you can right click the placemark icon, and save it, as either a KMZ or a KML . The KML is a specialized form of a XML file. The KMZ is a zipped version that for the most part, makes the data smaller. KML is easier to work with.

If you save as a KML file, you can look at the file in notepad, and the format is moderately obvious. (If it is not obvious, you are going to need a full course on computer stuff, and/or geographic concepts, or wait until there is a pushbutton solution)

Anyhoo, study it for a while, and if you are an excel geek, you should be able to coerce excel into creating a KML file for you.

KML files dont care much about line formatting and spaces, so use reformat the angle bracket tags into convenient variations.

You might try posting a more complete description of what you are trying to do in the KML forum. You may get a simpler answer.

Good luck.