It should have installed itself in the system wide Applications folder that any user can access. Open a new Finder window, click on Applications in the sidebar on the left and look if you can't find it as it should be there.
If it is just drap and drop it to all the way to the bottom of the Dock (Bottom Screen by default), wait until the other apps side out of the way and let go, and use it

And hang in there, it takes awhile to learn Mac OS but once you do it'll be easy!