A fan doesn't cool the computer as such, it moves air.
How far the temperature will drop inside your computer depends on the outside air temp, the temp inside the computer and how much air you are moving.
Installing an exhaust fan in your case at the rear could help a lot with temperatures.
The fan you have linked is PWM controlled, with a 4 pin connector.
To use this, you need a 4 pin header on your motherboard like the CPU fan header, but there often isn't one for system fans.
For a case fan you just want a fixed speed fan with a 3 pin connector.
You can then connect this 3 pin to a 3 pin header on your motherboard if there is a spare one, or to a molex to 3 pin adapter which connects to your power supply molex connector.