My 95 will not start, have checked for fuel at valve on fuel rail, OK...cleaned battery connections, I think it is not getting spark, what would be the first thing you would replace for no spark?

Remove a plug, put it in the plug wire and lay the plug on a ground. Crank it over. Do you have spark? No spark could be a bad crank position sensor.

Also check the coil there is a write up on how to do that defective coil will a deficient spark if any. https://www.gmforum.com/t278818/

I have had a couple 3800s where the metal plate under the coil packs will get some corrosion causing anywhere from a miss to no spark. If you are not getting spark at the plugs that is where I would start. It is easy to pull the coil packs and costs nothing to clean up a corroded ignition plate with a wire wheel or sand paper.