Hi Lauren, welcome to BonnevilleClub.
I had the same problems with the doors on my '89 Bonneville. It was the door handle itself on my car. The button that you push in to open the door has a pivot inside, and the pivit point was corroded up and siezed. I had to take my door panel apart ( NOT easy to do with the door closed
) and pull up on the rod inside. I then took the handle off and worked it back and forth with some good lube.
Where are you located? If a club member is nearby, he / she might be able to show you how to do it ( if that is you problem ). Also, you could possibly be able to get the doors open without taking the panel off.... if you can see the rod on the inside of the door that attaches to the handle. If you can see that, try to hook something on it and pull it up, then that should work for ya