Try running Wowza from the command line using startup.bat so you can see the log messages in real time. You'll want to verify that the stream is being published first, before you can play it. Look for lines like this:
INFO stream create - -
INFO stream publish stream1 -
If you don't then you'll want to re-read through whichever Wowza tutorial you are using, double-check for typos, and ensure your firewall is open on port 1935.