Screeching noise when I turn on my air conditioner or heater

No idea

Need the car to find out

YOU HAVE LOOSE OR WORN FAN BELT. when you turn off lights and aircon, it remove load on your alternator.

check drive belt driving altanator and air con it sounds like it needs adjusting

For the screeching noise you need to replace the blower motor and for the blower motor speed you need to replace the blower motor resistor.

Blower motor most likley. Does th efan work on all speeds?

The belt is slipping or the compressor and/or clutch is bad.
If the compressor won't turn freely with the engine off, it may be locked up which will make the belt screech.

the squeaking is caused by the fan belt becoming glazed over causing it to slip you need to replace it, if not that it can be loose bolts on the pulley system the belt runs through like the water pump, alternator and so on, nothing you spray in the aircon will fix it you need a new belt or tighten some bolts but its most likely the belt

Probably your fuel pump, have it looked at by a mechanic.

Actualy it can be front drive shaft,