First time PC builder. Why am I so sweaty?

xXReconTyrantXx6068

New to PC build and have dabbled in PC gaming for about 13 years. Im making the official switch from console. With more and more of my friends making the switch it’s time I do too. I’ve also been gaming on various laptops mostly MSI while I was into the army. So here’s my parts list my questions are. 
1. Do I have everything I need?
2. Will I be able to cool efficiently?
3. I it possible to water cool the GPU?? 

4. Am I in over my head and have made a terrible mistake. 

Here’s my parts list.

NZXT H9 Flow Dual-Chamber ATX Mid-Tower PC Gaming Case

ASRock X670E Taichi Support AMD AM5 RYZEN 7000 Series Processors Motherboard

MSI MPG A1000G PCIE 5 & ATX 3.0 Gaming Power Supply - Full Modular - 80 Plus Gold Certified 1000W

AMD Ryzen™ 9 7950X3D 16-Core, 32-Thread Desktop Processor

2X G.SKILL Trident Z5 Neo RGB Series (AMD Expo) DDR5 RAM 32GB (2x16GB) 6000MT/s CL30-38-38-96

WD_BLACK 2TB SN850X NVMe Internal Gaming SSD Solid State Drive - Gen4 PCIe, M.2 2280

Sapphire 11322-01-40G Nitro+ AMD Radeon RX 7900 XTX Vapor-X Gaming Graphics Card with 24GB GDDR6

Corsair iCUE H150i Elite LCD XT Liquid CPU Cooler

4x Corsair LL Series LL120 RGB 120mm Dual Light Loop RGB LED PWM Fan Single Pack (CO-9050071-WW)

Windоws 11 Pro

JakeVB

Welcome to the dark side! I was also a msi laptop guy myself and switched over! All in all, it looks like you’ll be able to stay cool While gaming! Any reasons why you’re going with Corsair fan/cooler aoi wise? There is definitely more on the market that will allow you to get more fans for the same price!  I’d recommend the Arctic liquid coolers if you want the few degrees cooler! Over the years, I’ve tried different coolers, and it seems to be the best cooling wise but that’s my two cents! With that GPU you’re gonna want a 144 Monitor! I’d also recommend getting a cable Extension set! Really takes your build to a new level cable wise! 

Lambdaben

I will answer your questions the best I can....

1. Do I have everything I need?

Besides keyboard, monitor and mouse, you have the basics of a PC build. However, I'm not sure if the H150i's RGB controller will control the LL120 fans......

2. Will I be able to cool efficiently?

Your case can fit a total of 10 fans, you have 11 in total (3 from the case, 3 from the cooler, and 4 LL fans) so, if you don't care if all the fans match, you will end up with an extra fan.

3. I it possible to water cool the GPU?? 

If you wanted to custom water cool your system, Byski makes a GPU block for that model 7900 XTX, but I would avoid the trouble if possible.

4. Am I in over my head and have made a terrible mistake. 

Building a PC is never a terrible mistake, it's a learning experience!

Hope this helps!!