I do not believe that Orion NPM can provide you this type of data. The only SW tool that might be able to help you (I think) is Orion Log & Event Manager (aka Orion LEM). After all, LEM does read Windows Event Logs, so you could possibly setup a rule to look for login/logout events. Still, even if LEM could collect login/logout events, I am also not sure if it could be customized to only report on first login and last logout events.
In any event, I am only guessing, based on what I have read about LEM since I do not even have LEM in our portfolio of SolarWinds tools. So, for this reason, I would defer to those in this forum who do have real LEM knowledge and expertise.
Best wishes.