Hi,
If you want to migrate all the data of a HikaShop to another Joomla website where you also want to use HikaShop, you can export all the hikashop_ tables in your database with PHPMyAdmin.
Then, edit the exported file with notepad to change the table prefix if it is different from the old website to the new website and then import the file with PHPMyAdmin into the new database.
Then, install HikaShop on the new website and it will find all the data.
The only things missing will be the modules/menus/plugins settings as these are stored in Joomla tables.
Also, if you wish to migrate the Joomla user accounts, you need to do it beforehand. There are many extensions for that on the JED.