I recently got a Wqhd 144hz monitor. Which cable should I get so I can take full advantage of Wqhd on the Xbox
An HDMI 2.1 cable or a DP cable. You also have to see whether the two devices support the cables and 144hz WQHD. The Series X does not support 144hz.
You shouldn't get any.
The new consoles come with a matching HDMI 2.1 cable.
However, both Series X and Series S support a maximum of 120hz. And not every game.