PWM fan + DHT22 on RPi3+

Hi.
I am planning to put my raspberry and my small low power SBC into one old PC case. The point is to have coolingfor both boards.
I have two 12V PWM fans installed in the chassis and I would like to control fan speed depending on the temperature inside the enclosure (or on heat sink, or both - using also ds18b20 - will decide after testing).
I could do it easily with esp8266 with espeasy on it, but this seems to be pointless, having lots of not used gpios on the raspberry. My raspberry is working as a HA server only and I never play with gpio on the board as everywhere I’m using esp8266.
Could someone give me some hints about how to start?
It could be nice if this could work independently from HA but with glace of temperatures and fan tacho speed or actual PWM setup for each fan
Much appreciated.

For the DHT, you can try this component:

I’m not sure about the fans.