Issues with installation of yii2 to the bare code base

Im very new to yii2, so theres a whole lot im unclear about.

I ran this code:

$ php composer.phar require "yiisoft/yii2:*"

And this is what i got:

./composer.json has been updated

Loading composer repositories with package information

Updating dependencies (including require-dev)

Nothing to install or update

Package yiisoft/jquery is abandoned, you should avoid using it. No replacement w

as suggested.

Package yiisoft/jquery-pjax is abandoned, you should avoid using it. Use install

via bower instead instead.

Writing lock file

Generating autoload files

Please, can anyone help put me through?