very very simple boost controller

Hello, I am new to the Arduino world and programming in general. I have managed to build a few small projects using LEDs and light sensors but I have no idea where to begin with what I even picked the board up for.

I would like to implement my Arduino Uno to increase the boost pressure in my 1985 volvo, first without a PID loop and once it is functioning properly I would eventually like to add the PID library and be able to use a few potentiometers to be able to fine tune the control of boost in my other car which currently uses a ball-and-spring style valve.

I have a GM 3 bar map sensor and a myriad of solenoids available but I think I would rather just buy a MAC solenoid brand new.

I don't know how to implement the sensor yet or how to drive a PWM device in the code, and this is why I would rather start this project as simply as possible and then dive into it a little further after I understand these basic things.

Can someone help me understand how to properly make this happen?