I'm pretty new at this too.
Nicole,
I think the first place you should start is try and find out why your dad parked it. Was the engine bad? Did the clutch go out? The starter went out? Just didn’t need a truck anymore? If you can find out why it was parked it can give you a starting point.
I would start by trying to get the engine you have now to run. If it will run, then look at all the brakes to make sure it will stop. It’s no good to have a truck that will go, but it won’t stop. That's a sure way to ruin all the fun of a classic truck. Check the wiring to make sure that you don’t burn it down before you get to drive it.
Once you get it running and road worthy, you can decide how far you want to go with the restoration. Do you want it to be a truck for hauling stuff? Do you want it to be a show piece? Do you want to hot rod it or restore it to original? I would advise driving it some before tearing it all apart. There are loads of projects trucks out there that people tear apart and never get put back together. Then you just have a pile of rusty parts that are no fun at all and really annoy your family and neighbors.
These things eat money like a kid eats candy on Halloween, so always keep your budget in mind as you make decisions on what to do next. That’s another reason I would advise getting it running and road worthy before anything else. Then you can save up for the next project on your truck while having fun driving it.
Just my 2 cents worth.
Stan