Good afternoon,
Unless you are running Enterprise Operations Console (EOC), you will likely not need the conversion utility. It is described here on page 32:
http://www.solarwinds.com/documentation/Orion/docs/OrionNetworkAtlasAdminGuide.pdf
Another useful guide, especially given this is your first install, would be the NPM Eval guide: It's a solid rapid-read way to get up to speed on things:
http://www.solarwinds.com/documentation/Orion/Docs/translations/EGs/US/OrionNPMEvaluationGuide.pdf
For deeper reference, I would be amiss if I didn't mention the full Admin guide.
http://www.solarwinds.com/documentation/Orion/docs/OrionAdministratorGuide.pdf