Where are you trying to run this report, AS or local machine?
Just to clarify you need a report server in local machine or report services to run the report through forms, both have different method to start.
What I think is you are trying to call the report in your machine (Window based). Here how you create and start a report server in your machine.
From the dos command window (go to the following path or run the file with the path)
<pre><Oracle DS Home>/bin/rwserver server=<server_name> [batch=yes/no] [autostart=yes/no]</pre>
For batch, the default is no. Enter yes if you don’t want to be prompted for confirmation during installation. For autostart, the default is no. Enter yes if you want the service to start automatically at reboot without requiring a user to logon and manually start the Reports Server.
Confirm that report server is running, run the following URL
Usually if the its a local machine and not on the network the URL could be