Here is where you can download pretty detailed instructions for MS3/TunerStudio. There are some things that will be different for the turbo Buick, and many setup things you should not change from the base tune.
http://www.msextra.com/doc/pdf/Megasquirt3_TunerStudio_MS_Lite_Reference-1.5.pdf
Here is a more detailed manual on software features. Again, much of it doesn't apply to the Buick setup.
https://www.ampefi.com/wp-content/uploads/ms3pro_manual152_module.pdf
http://www.msextra.com/doc/pdf/Megasquirt3_TunerStudio_MS_Lite_Reference-1.5.pdf
Here is a more detailed manual on software features. Again, much of it doesn't apply to the Buick setup.
https://www.ampefi.com/wp-content/uploads/ms3pro_manual152_module.pdf