nearly there but still not...

hi, i have started setting up .
1 i do not know if the blog is 'sitewide forums' or not
2 i created pages but cant see that they lead anywhere if clicked
3 are categories 'group' or 'forum' bound (here i must admit i am confused as to the role of a group and a forum)

to indicate what this blog should do:
it should create a space where less than 200 old schoolmates of 1971 can communicate - nothing fancy.
please help.
God bless