Would be hard to tell you were to look but some general things. First rule is always unhooking the battery before you start working on the wires. Check the ignition switch a good switch is snug when they get worn they will sometimes stick. Unhook your battery if you look close as you remove the cable you may see a little spark touch it again a few times this is a sign of a drain or short lots of causes. An alternator with a stuck diode is one you probably can have them test for free at some auto parts stores in your area would the first place I would look on a car that sat very long. After that you have to start unhooking wires one at a time to the different components i.e. charging, starting, ignition systems etc. Than recheck each with a test light, to track down a problem takes some time but is not so hard. You will need to find a good wiring diagram for the year of your car then start traceing the wires and if you don't know how the systems function pick up a book on basic auto electrical some good ones out there some may get a bit technical. Also a good visual look at the wires if you see cracked or cut insulation gets tape and fix it, and the wire terminal ends and connection points need to be clean and tight wire brush sandpaper etc. will take care of that. If the good thing is this old cars have a rather simple system. Also a good test light is one of the best tools you can have there are a few different types. One with a probe is a good start and maybe all you need there are also ones to find shorts, and a volt / ohmmeter is also helpful. Good luck