Second Time Building Pc

My first PC is getting errors and giving me problems so ive given up on it i was gonna buy a pre built but decided to build another. I feel i did good building my first one but any thoughts and advice is appreciated.

  • AMD Ryzen 9 5900x
  • NZXT Kraken X73 73.11 CFM Liquid CPU Cooler
  • ASUS Rog Strix B550-F Gaming WiFi II ATX AM4 Motherboard
  • Corsair Vengeance RGB Pro 32 GB
  • Samsung 980 Pro 2TB
  • MSI NVIDIA GeForce RTX 4070 12GB Ventus 3X
  • NZXT H9 Flow
  • Corsair RM850 W Gold Certified

The Rm850 is from my previous pc is it alright to use that one or should i just buy another?

I also have no idea how im gonna find a H9 at retail so i might just have to pay more for that, ill mainly be playing Valorant maybe some Destiny, Tarkov and a few others.