I'd say you first need to decide on the monitor, both resolution and size/technology, because that will tell us how much up the tiers we need to go with the gpu and how much money do we have for the actual PC i.e. there's a substantial price difference between a 27" 180hz IPS display and a 27" 180hz Oled display and there is a substantial price difference between a 24" and a 32" monitor in general.
Once we know the monitor, we can establish the best price/performance gpu with that monitor. And then we can figure out the rest of the build with the remaining budget.
If you're only gaming CPU really isn't that important, you could get by even with a ""low tier"" CPU.
So first things are : what games are you going to play? are you going to play competitive online? do you in general prefer higher FPS or better image quality (like "i cant's stand playing under 100fps" or "I don't care if it dips below 50fps, as long as it's smooth and looks stunning").
How much space do you have on your setup for a monitor, both in width and length (bigger monitors mean you want to be further away from them, not all desks are that deep)?
How much does good contrast/deep blacks/good color mean to you? Are you going to watch movies too on that monitor or are you only going to play? Are you going to do some office work also? etcc etcc..