Hi,
For configuration details ; please provide screenshot. It will be easier for you and for us.
You can manage the custom fields in the "HikaShop > Display > Custom fields" section.
And regarding the HikaMarket configuration ; your problem is related to your Joomla registration settings.
HikaMarket will activate the vendor account when the Joomla user will be activated ; but that part is handle and entirely managed by Joomla.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.