The author of the addon didn't provide any scenarios. Since the addon doesn't overwrite the original dll you have to create your own ones. There are two possibilities:
1. Load the TX via the scenario editor. At the bottom of the list you will find a folder called "Total Immersion", here should be the TX with virtual cockpit.
2. This is what I did. Just go into your Orbiter directory, go to Modules/TotalImmersion and copy TX.dll to the folder Modules, let it overwrite the original Tx.dll. This way you have virtual cockpit in every scenario provided with the original TX. Don't forget to backup the original dll, if you don't like it!