I installed meteor and created an app following tut http://docs.meteor.com/#quickstart
In finder, I searched meteor but I can't find it.
/usr/local/meteor - you can find that in the install script from http://install.meteor.com/
As a more general solution, the bash shell command type accomplishes this for any command:
$ type meteor
meteor is /usr/local/bin/meteor
For other shells, see this excellent answer over at superuser.