how to crank engine from under the hood for my 1995 GT

If you press the accelerator to the floor when you attempt to start, it will avoid adding fuel and help blow the spark plugs clean of fuel (it's 'flood clear' mode).
There's really no good way to set the timing accurately without a timing light, but I don't think a few cranks 180 degrees out would irreparably foul them.

As far as I know, I think you could jump a wire to the blade-connector on the starter solenoid which is on top of the starter itself to crank from the bay. I don't think there's any easy way to do it otherwise - or an exposed connector to jump. The easiest thing honestly is to have a friend / roommate / girlfriend / spouse / neighbor / neighborhood kid crank it for you while you check on things. Gives you an excuse to make a new friend anyways, or to annoy the wife. My kids have been assisting since they were in diapers.