Hello,
Follow the plugin documentation to create vendors https://wc-marketplace.com/knowledgebase/setting-vendor-registration-wcmp/
If you have more questions about WCMp plugin settings contact plugin author https://wordpress.org/support/plugin/dc-woocommerce-multi-vendor/
We are able to help you with theme options only. The questions you asked are related to the multivendor plugin.
Regards
