The hardware (PS5/PS4) should come with everything to connect to the TV - power leads, HDMI cable, 1 controller & charging cable. You’d also need to purchase a second controller for your gf if you’re both going to be playing the game together.
If you’re buying pre-owned then sometimes these are missing (especially the charging cable) so double check what’s included.
Thanks Anankha. You mentioned HDMI cable: I noticed my local stockist says the PS5 has optical out. Does the PS5 have both optical and HDMI ports?
Also, where does the PS5 box sit? Near the TV? Or near the users? I'm guessing that if the controllers are wireless the box must be close to the TV?