Car shuts off when put in drive

You have a vacuum gauge? A timing light?

Do you know your initial timing setting? If you can't answer this, you need to find it.

What happens to initial when it's put in gear? Does it lower itself?

Quick test before you do anything else. Start the car, loosen the dist hold down and turn the distributor body a little bit counterclockwise if SB, clockwise if BB. If the engine picks up RPM, it wants that additional initial timing or more, now you know what you need to do. Reset the idle speed and do it again. See what happens when the car goes into gear after you up initial.

If you have a vacuum gauge use it to see how far it wants the initial. Max vacuum, then back off timing so it drops 1", resetting idle speed. I have run in some cases, as much as the starter will handle without kickback.