Heater fan is making noise when on

Air/heater sounds like an airplane, my car has 147,306 miles. The car was wrecked a year ago not too much body damage, but now if I turn the heat on full blast, it makes a "eerr" sound. I was thinking it was my fan, but im not sure. It also leaks fluid on the driver side floor. I think maybe now its my fan motor and my thermostat. I have never worked on a car in my life, but I have kinda made this my side project lol. I intend on doing the work myself, so any advice would be greatly appreciated. :)