How to use CjBlog

Yesterday,I installed cjblog and corejoomla API. But I have no idea about how to use it. I am very confused with it. I want to use CjBolg to make a social blog not just one personal blog which bloggers are my classmates.I just saw the "boddunan.com" website which is close to my goal.

Here are some question about using CjBolg:

1. It seems has a error with bootstrap.It happens whether I disable bootstrap or not.My joomla version is 3.0.3 and my template is yoo_nano2 which is useing bootstrap.This is the most important problem,please help me to solve it. :huh:
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2.How to upload image to User Avatar.Does any other author upload his user avatar on the same way?

3.Already there has 2 categories in my website : blog and about-us.The strange thing was that the post under 'about-us' category show like this:
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The 'blog' category's posts has no sytle:
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My website: http://42.120.21.87/

thank you very much. :)