meta tags for home page

Hi
Does anyone know how to control the meta tags for the home page of directory ie title, description etc?
I have pages set up for the other pages which all can be altered with the SEO plugin Yoast but as the home page is not an actual page here I dont see any option to change the tags?

Also for each business listing submission – can they control their meta tags for their listing?

I had a look at one of my test listings and I can see it automatically takes the listing title and wordpress title and uses the listing description for the description tag which should be ok but it seems to have my site title twice in the title ie

<title>Website Design – Poppy Design & Graphics – Find a Moray Business Find a Moray Business</title>

Can anyone advise how to only have one site title here please?

Thanks
Joanne