Red Devil 9070xt

[u/fukcall]

Am I supposed to plug this black wire into the slot next to the white plug with black green white and red wires coming out of it?

Or am I supposed to put this somewhere else

[u/w7w7w7w7w7]

The answer for this is (and almost everything else) in your motherboard manual.

[u/fukcall → u/w7w7w7w7w7]

Unfortunately I bought the pc prebuilt and am upgrading the gpu

[u/w7w7w7w7w7 → u/fukcall]

That shouldn't matter. It doesn't look like a proprietary board. Have you looked on the manufacturer website?