major change

i want to build a community , but i`m not so good in PHP. i want to make some changes in WP and i hope i will got the answer.

i try to explain how i want to make the page:

when u open it, the 1st will contain the user name [fonts size will differ about how many post they have], also the tags they use. when u select a user, another page will came, where the post will be showed, and a picture and a about part on the page. no categories, no blogroll and other things. the post normally can be commented.

how i can make this ? i think about it, the users can be like categories, but i can restrict other users to post there, and also i cant figured out how to add category when a user register to the page

[sorry for my bad English, i hope everybody understand how i want to make it]