That’s often a sign that the battery has lost its punch, so start by checking the battery condition. Also check the battery terminals and clean them if necessary. If the battery is fine and the terminals are clean you could look at the starter itself.

You can use regular unleaded or the E10 ethanol blend. Swap meets are good places to find things like owner's manuals, and you could also try e-bay.

It’s likely to be the gear set that’s causing the noise, have an auto trans specialist drive the car for you for a more exact diagnosis.