How do I control fan speeds on my new build?

I can suggest three options, all of which will do what you want.

1. Buy a 4-pin fan HUB like this

https://www.newegg.com/Product/Product.aspx?Item=N82E16882422018&cm_re=coboc_fan_splitter-_-82-422-018-_-Product

It looks like a circuit board with 8 output ports, but its labels suggest it should be used with up to 5 fans - fills your needs - although I suspect you could use all eight. Other Hubs may look like just wire arms (below) or like a box with ports. The key factor for a 4-pin HUB is that all power for the fans is taken from a 4-pin Molex power output connector from your PSU; this avoids overloading the mobo fan header. The PWM control signal for all the fans (they all share the SAME signal) is taken from one mobo fan header that is using PWM Mode. As with ALL Hubs and Splitters, the speed of only ONE of the fans will be sent to the mobo port for display - the header can only deal with one speed signal - and speed of others will be ignored. With this device, all five of your case fans can be controlled identically from ONE mobo CHA_FAN header.

2. Less expensive, buy this type of HUB

https://www.newegg.com/Product/Product.aspx?Item=N82E16812423166&cm_re=coboc_fan_splitter-_-12-423-166-_-Product

It looks like just a group of wire arms, but it works exactly as the circuit board type does. This one has 5 output arms.

3. Buy two SPLITTERS like this

https://www.newegg.com/Product/Product.aspx?Item=N82E16812423162&cm_re=coboc_fan_splitter-_-12-423-162-_-Product

This is a different device. It does NOT get any power from the PSU. All fan power is drawn from the mobo header is plugs into. But each such header can supply up to 1.0 A total, and your fans draw at max 0.13 A, so having three of them per header is no trouble. Cost is comparable to option 2. The only advantage of doing this is that you can group your fans onto smaller groups - 2 or 3 per header - so you can "see" the speed of more of the fans (one per header) and MAYBE customize the control details of each group IF you want to. Using two of these Splitters, you could group two fans each on the CHA_FAN 1 and 2 headers, and plug the last fan into the CHA_FAN3 / PUMP header. OR, you could skip that last header and plug three fans onto one of the other headers.

Whichever you choose, configure the fan headers you use in BIOS Setup this way. See your manual, pp. 83-84.
(a) Set the "CPU Fan 1 Setting" to "Standard" or something similar that will use the automatic control system to adjust fan speed according to a temperature sensor built into the CPU chip itself. For now, I do not advise setting up a custom control curve until you know more about that and decide you need something special.
(b) For EACH CHA_FAN header you are using, set it to "Standard" also. Set its Temperature Source to use the sensor on the motherboard, not the one inside the CPU chip. IF you are using the CHA_FAN3 / PUMP header, set it operate in fan mode, not pump mode. Ensure it is set to PWM Mode, not DC Mode. And again, set it to use the motherboard temperature sensor.

When you have made all your changes in BIOS Setup, remember to use the F10 key (or click on the Exit icon at upper right) to get to the Exit menu, then SAVE and EXIT to save all your new settings.

Whichever route you choose, this will put all of your fans (CPU and case vent) under automatic control. This means that, based on actual measured temperatures (inside the CPU chip for the CPU cooler, and on the mobo for the case fans), the mobo will constantly adjust the speed of each fan group according to cooling needs as workload changes.

warm pancake
That is why you always read up on what you are buying

But there is no reason for me to answer a question that Paperdoc has answered

I will say tho that I have no experience with the fan hub he posted so dunno about the quality but I dont think he would post something that would break in 1 week