74 340 Cuda! what should i do?

My Dad gave me the chance of getting his cuda up and running again. as long as i dont f*** it up or anything he said i can try and get it running. here is how it goes, when we had moved to our new house 18 years ago the one we live in right now my dad brought the cuda and put it in the garage and had done anything with it since! now he wants to get it running again. what should i do before i bother to run it again?