WordPress install, plugins (install and configure), and set up one advanced plugin*. Provide support for the advanced plugin (configuration/updates), this does not include fixing errors with the plugin (contact the developer). Pending on the plugin there may be further fees from the plugin/add-on provider or service required by the plugin/add-on. Also, regularly checking your website for out of date plugins, themes, translations, and WordPress itself and updating them.
* An 'Advanced Plugin' is a plugin with extensive configuration and/or requires manually uploading and installing into WordPress. Woocommerce is a good example of an Advanced Plugin as it requires extensive configuration and has paid options not available at WordPress.org plugin library.