Sidebox Module and search product in free version

Hi,

Yes that's possible, even with the free version.

You need to create a new hikashop content module via the joomla module manager. Assign it to a valid position of your template and publish it.
Then, in the HikaShop options of the module, set it to display products randomly, check that the "associated category" is "product category" and that the "sub element filter" option is set to "all sub elements".
That's it, it should not work.

For the search, you should publish and configure the hikashop products search plugin via the plugins manager of joomla. Then, publish the joomla search module to a position of your template via the joomla modules manager and it will work.