Cinemachine for green screen background

I would like to create a background environment (street scenes) using cinemachine and then combine with foreground actors plus motion tracking.

Is it doable?
Do I need high end computer to accomplish my goal?

Thank you.

 

Don't know if this helps, I used a digital shark from the asset store..Not sure about your actors? But this''

was made into this

by using just the default Unity camera with a pure green background and then recording with Renderhead.
The wriggly bit of the shark done with a Camera filter pack.
Although recording with any (cheap,free) asset would also do the trick.
The original water scene was with a average movie camera.
Good luck.