Welcome to Tom's Hardware, @Marcin8t!
Your motherboard definitely incorporates SATA ports, I'd advise you to check your model's user manual for details on how to physically install the storage devices inside. If you don't have the manual, check the official website of the mobo's manufacturer and download the manual from there.
Once you have found the SATA ports and you have set up your PC properly, you could also refer to our kB article on
How to install the HDD inside (steps 1. Physical installation). You need to make sure that the drive is connected both to the motherboard (via SATA cable) and to the Power Supply Unit (PSU) via the Molex cable.
Hope it helps you. Let me know if you have more questions.
SuperSoph_WD