Hi,
I'm not following you. There are already phone and address custom fields by default in HikaShop. You can find them in the menu Display>Custom fields of HikaShop after you installed it.
Reading between the lines of your message, I'm supposing that what you're asking is actually that you have Joomla profile fields for your Joomla user accounts and you want to prefill the address fields of HikaShop with these, is that correct ?
To do that, you need to develop a plugin to prefill these fields when displaying the address creation form.
Rather than doing that however, I would rather recommend that you don't use the Joomla fields and don't use the Joomla registration form, but instead, that you activate the "Redirect Joomla registration to HikaShop" plugin via the Joomla plugins manager, in order to use the HikaShop registration form instead of Joomla's. That way, it will already have the address fields during the registration and customers won't have to fill in their address twice as it will directly be stored in HikaShop's custom address fields.