Adding RAM to current PC

[nathphotographs]

Hi, I'm looking to add another 16GB of memory to my current PC. From what I understand, I can purchase what I currently have, put them in the 2 spare slots and that's about it? I'll also be adding a HDD as well, probably a 4TB one. 

 

Current setup:

MSI MPG Z390 Gaming Edge AC 

Team T-Force Dark Z 16GB (2x 8GB) 3600Mhz DDR4

 

https://www.pccasegear.com/products/48310/team-t-force-dark-z-16gb-2x8gb-3600mhz-cl18-ddr4-grey

https://www.pccasegear.com/products/44217/msi-mpg-z390-gaming-edge-ac-motherboard

 

I currently have that setup and just looking at buying the exact same memory and adding it and a HDD along the way. 

 

Any help is appreciated if I'm wrong and it doesn't work this way. 

 

Nathan