Don’t worry, you can easily activate the revolution slider.
If you go to WordPress plugins page you will find it, just press activate. Or go along with the notification that appears to you.
Then after you activate the plugin:
Create a new slider with the name ‘engineer’, or any name you want but you will need to edit the block in the home page through the builder, and modify the shortcode [rev_slider alias=”engineer”] so that it match the alias name of your created slider.
Or if you want the exact slider used in the demo, let me know and i will send you the xml file, so that you can import it within the revolution slider.