Totally new to all this but looking to buy an ET8000 & already have a spare 500GB Sata drive so was wondering how easy it was to install it?

I'm assuming the ET8000 has a spare power cable & Sata cable. Is there a slot for 3.5" HDD?

What formatting would I need to do & will I need to install multiple partitions. Is the formatting done with HDD in pc or in ET8000?

I can generally find my way round the inside of a windows pc but no experience of linux whatsoever so any assistance or a location of a guide would be much appreciated.