It should work, assuming you do nothing else than double-click on Audacity.app.
All you did is force quit Audacity. In the highly unlikely event this damaged the app, drag the entire Audacity folder to Trash and install Audacity 2.0.6 again following Installation: Do NOT run Audacity from the DMG!!!.
I have Yosemite and Audacity does not to fail to open.
If you have other reasons for reverting to Mavericks, back up your files to an external drive or cloud storage then follow http://www.macworld.co.uk/how-to/mac-software/revert-back-mavericks-from-yosemite-3581872/.
Or you could keep Yosemite, create a new partition in Disk Utility then install Mavericks into the new partition. You can then boot into either Mavericks or Yosemite by choosing the Startup disk in System Preferences. You can restore your data into Mavericks from the external or cloud backup.
You won’t find Mavericks online. If you need to redownload it, do so from the purchases section of AppStore.
Gale