How do I import a plugin into WordPress?

In WordPress 2.7 and above you can install plugins directly from the admin area. Download the plugin to your computer, then log in to your WP admin area and go to Plugins > Add New. Browse to the plugin archive and select it. Then click Install Now and the plugin will be installed shortly.

Why cant I add or install plugins in WordPress?

WordPress.com users cannot install plugins unless they upgrade to the business plan which costs about $299 per year. If you are on a free, personal, or premium plan, then you cannot install third-party plugins. If you dont want to pay the $299 per year, then you can move your blog from WordPress.com to WordPress.org.