Ya might want to list more details about this if you haven’t already found a developer for this. For instance, devs may need to know what kind of interactions the website needs to have with the server. It may require them to hook into third party utilites. Also, if you want a CMS (a panel to manage the site’s content) as well to help you manage the website, or if you’ll need to re-hire someone to alter the website each time.
There tends to be a lot of nit picky things that need to be done to support a functional website. In order to handle logins, news feed, etc, they’ll likely need an SQL database and to code a system for allowing secure logins, etc. If you don’t have another service to implement the shop, they may need to use another 3rd party utility for that. May also help to say if you want to use a pre-existing CMS, such as WordPress.