After activating the theme, go to theme dashboard, in the sidebar menu. To install the plugins (WordPress Admin > Deep > Plugins) click on install, then on activate.
After installing the theme, you can activate the plugins you like.
Just remember, you can access the plugins from this panel any time. Here you have the options to install, activate, and deactivate plugins. You can also access the plugins by going to WP-Admin > Plugins.
One more thing. If you want to install new plugins (not the ones that are included in the theme) you need to go to WP-Admin > Plugins > Add New.Managing Plugins