I'm brand new to Sonar Platinum.  Can anyone suggest how can I load Sound Forge and get access from Sonar Platinum?  I'm very much a rookie.

This should help, but ask if you have any questions.
http://forum.cakewalk.com/Question-about-editing-in-an-external-wave-editor-m3384952.aspx
 

https://www.cakewalk.com/Support/Knowledge-Base/2007013099/Adding-third-party-audio-editing-software-to-SONARs-Utilities-menu

That is the official link, but need to tailor the process to your specific version of SONAR.

If you prefer not to edit the registry directly take a look at SONARToolsEditor. It is about a fourth of the way down http://forum.cakewalk.com/FindPost/3392713. I also wrote an additional utility which will launch programs like SoundForge as administrator (which it needs) without having to run SONAR as administrator. The program is on the same page.

Use scooks tool, it's the way to go for this.