I figured out that I had to select BP as the default theme, which overrode my current theme and messed things up. I have to do more investigation as to whether I can use this plugin with my theme, or how to install it so it is compatible. Thanks for the response!
I have the same problem, I think. I have downloaded BP and run the installation wizard, and gone through the BP settings. However, Buddy Press does not show up on the list of Settings on left side of WP panel. I have no idea where to start without that (according to your support on setting up groups elsewhere on this site).