WordPress’s Jetpack services allows you to create posts and “Publicize” them immediatley to your social media accounts.
What you will need to do is to firstly create those media accounts before you can publish to them. Dunjoko Designs will build your website, and install Jetpack for you to set up your social media links. If the computer that you are working on has been used to sign into any of the social media accounts, then Jetpack should be able to connect up to them without issues
You will need to also create a WordPress account at http://wordpress.org