74 340 Cuda! what should i do?

I have never seen a paint job like that before. Very cool.
Before you get a new battery and turn a key, I would tell you;
Basic tune up parts.
Marvel mystery oil the cylinders
rotate the engine by hand a few times after the marvel soaks for a few days.
Take distributor out and with a drill, use a priming shaft to get the oil pump ,
to run up some oil through out the engine.

Rear end and tranny fluid change
Change shocks and check all bushings.
Then get new brake pads and shoes when you take the tire off to get new ones.
Double check electrical connections.

This is what I do on my ('73) Cuda. Sometimes it sits several years before I get it going again.