Communities Plugin help

Hi, I am new to Wordpress Multiuser, I have downloaded the communities plugin as it is exactly what I am looking for, especially the wiki element. But this may be a silly question, but does buddypress have to be installed with the communities plugin? As I don't have any menu item for groups or friends etc. I even installed the communities theme, but I still only have home and about in the menu bar.
I also wanted to ask, is it possible to have 2 communities, as I would like to have one group that would have to request new groups from the admin, and another group that can be set up by the users themselves. Perhaps, buddypress and communities together? And a final question, can you change the name, for example I would like to have guilds, and clans, rather than groups.
Thank you,