That info got the right manual for me, so thanks. This mobo's BIOS does not have a lot of fine detail features on fan control. It has only three fan headers, of which only the CPU_FAN one is pertinent to your situation. That is where your CPU cooler fan is plugged in. The only item I note for you to check is mentioned on manual p. 2-17, under "Smart Q-FAN Function". That is the way to activate the automatic fan speed control. The manual say that, by default, this is set to "Disabled", so the mobo would NOT try to control fan speed. IF that is what you find in your BIOS Setup screen, change it to ENabled.
OK, back up. You said you have little experience with this stuff, so I'll walk you through. Start with the manual, p. 2-5. BIOS Setup is the built-in utility for customizing a number of settings in your basic system. It consists of many screens with menu items to observe current settings and make changes. To get into this system, you must re-start your system and immediately push and HOLD DOWN the "Del" key. If you only tap the key, it may not notice your simple tap. Wait while the system goes through a few start-up things and then shows you the main opening screen of Setup (p. 2-6). Use your cursor keys to move across the top to Power, then down in the middle of the screen to the item HW Monitor Configuration, and hit Enter. See p. 2-17, Section 2.5.5 for the items in that menu. Use the cursor-down key to get to the Smart Q-FAN Function item, then choose the Enabled option. (Usually do that by highlighting the option and hitting Enter or Space Bar.) Use the Esc key to go back to the Main Menu, then at the top go over to Exit Menu and hit Enter. See p. 22, choose Exit and Save Changes to save your new setting and reboot.
This should tell your mobo to use its automatic fan speed control for the CPU cooling fan. Its normal operation will start up that fan at full speed on every boot-up for a few seconds, then slow it down to whatever is needed according to the temperature sensor inside the CPU chip. From then on as that temperature changes with workload, the fan speed will be re-adjusted continuously for you. Generally it will NOT run full speed, so it will be quieter, but you may see your CPU internal temperature running a little higher than it used to. After all, what is happening now is that the CPU is being over-cooled by a constant full speed fan.