If you want to reach out to hosts in your target market, the best way to do this is to set up your own marketing channels i.e. FB page/website etc and use them to identify why hosts should choose your service and then you can invest in online ads to drive traffic to your site. @Lacey46
You can also join local host groups and become a trusted member through offering comment and your expertise so that when hosts there ask for co-host recommendations you can volunteer your services.
You could also approach established property management companies in your area and see if you could work for them to build up your experience.
It's against the terms of this forum to use it to advertise commercial services such as co-hosting.