Are hhd and ssd cables the same? SATA and the one for the power supply? Is there a extension for either cable? If so what are they called? I’m completely new tho all of this
Yes, both (2.5"/3.5") use SATA data cables & SATA power cables.
There are extention cables however I've never had to use them as the included cables (SATA data) are typically long enough if you do the cable management properly.