New user - Lightroom won't launch

Hi there - I just installed the Lightroom cloud-based software on my MacBook, along with Creative Cloud. The CC software launches, but LR does not. I keep getting an error message (actually, 2 error messages in two separate pop-up windows: one says "Sorry, an error occurred" and asks whether I want to report the error to Adobe, and the other says "Adobe Lightroom Closed Unexpectedly" (although it never actually opened). I tried rebooting and signing out and back into Creative Cloud. Any suggestions?

Thanks!