2000 Chevrolet Prizm dashlights

My dashlights stop working. All other dimmer lights still working, all fuses are good. Is there another bulb behind the dash or. Not sure what to do. And I'm going to need a new battery its not holding a charge and it looks like it is a little swolen. Need the size for replacement. There are no markings on it. But and this is kinda odd the engine light was on so now I'm thinking it was a battery light, but after tring to start it one day, the engine was straining to start and the light went off. If u could give your opinion on that too thanks guys.