I have a 86 chevy camaro and it keeps cutting off after i put it n gear

Did it start doing it after driving for a while and coming to a stop with car stalling? Then started up fine and stalled when you put it in gear like it was a manual trans? If so it'd your lock up torque converter staying engaged . Changing lockup solinoid inside trans pan usually fixes it.

Idles to low but if you keep foot on gas will run fine. If so Probably your idle air control valve. Also have you cleaned engine lately(water on it). If so might want to test your throttle position sensor. They don't like water at all.

Haven't cleaned it and it does it when I change from park to drive and if I'm driving and come to a stop

I would start with cleaning or replacing the iac and cleaning the throttle plate. Tried to clean the iac on my 85 z28 and it fell apart. So might be prepared to buy a new one just in case. If neither of these helps then test your throttle position sensor for proper operation with multi meter. There are three wires going to it. With key in on position(car off - not running) one wire should have a steady 5volts on it all the time. One is a ground all the time. The last one should start at .5 volts with throttle fully closed (idle) and smoothly increase to 4.5 - 5 volts as you move throttle to full open. Voltage should smoothly climb and fall with movement of throttle. If it does not always start at .5 with throttle closed and smoothly climb to 4.5-5 when throttle fully open then it's bad and needs to be replaced.

Might also want to clean maf sensor too. But used only maf type cleaner on it.