I have a Chevy and it starts up but when you put in gear it stalls would it be the starter or something else?
Something else. The starter is used to “start” the engine and is disengaged once it starts. The most common cause for this would be the TCC Torque Converter Clutch solenoid. In most cases if you can unplug the TCC solenoid (5 in diagram) at the transmission and the stalling issue will go away. However the converter will no longer lock up. This will leave you with the impression that you no longer have overdrive. Rest assured, you can drive the car this way for as long as you would like or until you decide to drop some serious coin and have it fixed.
The TCC Solenoid
The TCC solenoid is what actually causes the TCC to engage and disengage.
When the TCC solenoid receives a signal from the ECM, it opens a passage in the valve body and hydraulic fluid applies the TCC. When the ECM signal stops, the solenoid closes the valve and pressure is vented causing the TCC to disengage. If the TCC fails to disengage when the vehicle comes to a stop, the engine will stall.
Source: ThoughtCo.com