Thank you CaseySJ for the easiest build ever and for this guide. No issues at all. Thanks too to WhenMusicAttacks for your tips finally got the plain 10900 no K and it goes fast as hell 4,6GHz from scratch I owe you 100 quid.
for anyone interested this are the final components I assembled:
Gigabyte Z490 VISION D
Intel Core i9-10900 2.8 GHz
NZXT C750 750W 80 Plus Gold Modular
Sapphire Pulse Radeon RX 580 8GB GDDR5
Be Quiet! Shadow Rock 3 CPU 120mm
Corsair Vengeance RGB Pro DDR4 3200 PC4-25600 32GB
Be Quiet! Pure Base 600 USB 3.0
Sabrent 512GB Rocket NVMe PCIe M.2 2280 SSD (for OSx)
Western Digital WD Verde Internal SSD 2.5" SATA, Verde, 1 TB
Still untested: thunderbolt 3