Create widget area for sidebar on responsive theme homepage

I’m using a responsive wordpress theme to build my new website (https://kwma.fredserva.fr/?themedemo=kwma).
I would like to create a widget area on the right hand side of the homepage (https://www.waziproject.com/wazimagazine) in order to have a sidebar on the right hand side in which to showcase banners.
I’ve tried using code from https://www.responsivegridsystem.com/, but I’m simply not managing.
I guess in the end I just need to create a column within the container before the loop starts, right?
Any help would be tremendously appreciated!