finding my tomcat on my machine

The default Tomcat installation directory should be: C:\Program Files\Apache Software Foundation\Tomcat 6.0

Answers

There are a few things to note.

The readme file for xampp's Tomcat addon has what you are looking for http://www.apachefriends.org/winxampp/readme-addon-tomcat.txt It indicates that

Tomcat Server Home  =   .\xampp\tomcat
Tomcat URL          =   http://127.0.0.1:8080/
Tomcat Doc Root     =   .\xampp\tomcat\webapps

Tomcat example Root =   .\xampp\tomcat\webapps\examples
Tomcat example URL  =   http://127.0.0.1/examples/

So your web applications should be going under the .\xampp\tomcat\webapps directory

Also what version of the JDK do you have installed? The error message cannot find current JDK installation indicates that you don't have a version of the JDK installed or setup properly.