Hydoxuos

Oof, in my country the 240 mm isn't available and the 360 mm is like €180 😐
 

Well the cpu has 24 lanes, on zen 2, 16 is for the GPU and 4 is for an m.2 slot. 
As for the pcie lanes that are wired to the chipset, they're all gen 3, and you can look at the pcie layout on the manual for the board. 
Usually if you place an m.2 in a slot that is wired to the chipset some SATA ports do get blocked.  
As for the second pcie slot, other than it being at 3.0, while it is a x16 slot it isnt electrically, meaning it doesn't have the full 168 pins that a x16 slot has. 

Nice overall build!

Looks pretty good.
Swap the CXM for the Corsair TXM 550W. Its only 3 euro more and its an excellent unit for the price
I would also suggest getting the MSI B550m Pro-VDH wifi if you can stretch the extra 10 euros. Its a better board all round and will handle more powerful chips better if you want to upgrade in the future. Its also got wifi which may be a bonus for you. If you cant stretch to this the aorus pro is fine. If you dont plan on getting a more powerful chip like the 3950X, or dont think you'll ever want to overclock something like a 3900X, the Gigabyte B550M DSH3 may be worth considering to save some cash.
 
Otherwise choices look good. Hope this helps 

Alright, thanks! 

Thank you so much! 
 
What do you mean with "just fine"? Will it run OK or great? (if you understand what I'm saying) 

Okay, thank you!

Yes.

yep, it's just a normal USB C cable. i'm currently charging mine with a cable from my phone.

Okay, thank you! 

Well, I am gonna wait after the 30 series from Nvidia. People say it'll come around september, I think prices will drop than.

Well, I made a list. I already made a post to get some tips... 
https://pcpartpicker.com/list/
(the 3 3300x is 130 tho)

Well, I made a list. I already made a post to get some tips... 
https://pcpartpicker.com/list/
(the 3 3300x is 130 tho)