Your case has room for only one front 120mm intake fan.
Run HWmonitor.
It will tell you the current , minimum and maximums for cpu and gpu temperature.
Also the fan speeds of the cpu, gpu, and case fans.
80c. under load is a common temperature for graphics cards. You are not really bad off there.
On the cpu temperatures, look at the idle(minimum) temperature.
Much more than 10-15c. over ambient and possibly your cooler is defective, not mounted well, or does not get sufficient intake air to let it do it's job.
If you see a max of 100c. your processor is likely throttling.
Try a simple cpu stress test using the bench tab of cpu-Z.
85c. is ok. Normal gaming, 75c. is ok.
If anything is too high, what to do??
Your only two options:
- Buy a better cooling case.
- Increase the intake airflow of the front 120mm fan.
This will come at the cost of more noise.
900rpm is all but inaudible.
1200 rpm is not particularly noisy.
2000 rpm might be tolerable.
Even 6000 rpm might be possible,
A 2000 rpm normal fan might be $12.
https://www.newegg.com/cooler-master-r4-c2r-20ac-gp-case-fan/p/N82E16835103061?&quicklink=true
You pay thru the nose for rgb bling, perhaps $30 more:
https://www.newegg.com/corsair-co-9050091-ww-case-fan/p/N82E16835181167?&quicklink=true
No need to do anything about the 120mm exhaust fan.
Whatever air comes in the front will eventually exit somewhere, taking component heat with it.
The rear fan is there mainly to direct airflow across the cpu cooler and graphics card.
And--- if you can put a filter on the front, your parts will stay cleaner.