Inspiron 5680, CPU-GPU-PSU-RAM upgrade options

Hi all, 

I bought an Inspiron dt 5680 on july 2018, I am looking now to do some upgrades instead of buying a whole new pc. These are the specs of my pc :

- Intel® Core™ i3 8100 (4-Core/4-Thread, 6MB Cache, 3.6GHz )

- Intel Z370 mobo (I guess)

- Chassis with EPA 460W

- 8GB (1X8GB) DDR4, 2400MHz

- NVIDIA GTX 1060 3GB

So, what's the best combo of CPU-GPU-PSU-RAM I could upgrade my pc to? I only use it as a gaming pc, I am mainly into simracing.

Thank you very much.

ps. please consider I am quite a noob in regards to that subject, so bear with me and keep it simple, thanks!