I am the biggest computer retard ever and my knowledge is limited to playing vidya. I want to know your advice to the specs and pic related, my computer that my cousin built for me 3 years ago. It runs well but my brother has almost the same as mine and he had problem with the CPU, it overheated

Here are the specs:

>Motherboard: ROG Strix B550-F Gaming wifi
>Monitor: Asus VG27A
>Power supply: Rosewill 850w 80plus bronze
>Case: Fractal Design Focus G Mid-Tower ATX with 2 front fans, no fans at the rear
>GPU: Nvidia Geforce RTX 3080 msi
>CPU: AMD Ryzen 5900X 12-Core processor
>RAM: 2x16GB Kingston DIMM DDR4 2667MT/S
>Storage: 1TB SSD kingston SA2000M81000G
>Heat sink CPU: Not sure but seems to be generic AMD Wraith air cooler

Anything wrong with it? I'd like to add a 2 or 4TB memory because I want to get into gamedev using UE5/blender, maybe change the heatsink and add a rear exhaust fan

Also, what kind of maintenance/optimization do I need to do? I just gently air spray it outside to remove dust but what else? I'm afraid to play in the settings/guts of the computer as I am a total noob. Do I need to tinker with the BIOS? Do I need to defrag my memory? Do I need to play in the settings of windows/nvidia? I just want it to last a long time, keep it cool and quiet. I don't know where to look for basic computering 101 :(