I suggest working right through a good tutorial such as
railstutorial.org (which is free to use online). That will show you
the basics of Rails.
To answer your question however you just have to edit the erb files in
app/views/tests. You may have to provide appropriate CSS also of
course. But do the tutorial first.
Note however that it is not a good idea to have a model called Test, I
think you may run into problems with test being a reserved word.