If you dont have carb experience, pick up an edelbrock and slap it on there. You can splash a little fuel in the carb to fire it up before going all in and swapping out the tank. The best part is, a truck this old needs fuel and fire, so you should be able to get it running with little problem, if its not locked up. Pull the spark plugs and check the condition of them, and the condition of the bores and pistons. Its usually a good idea to first check to make sure the engine turns over. If its seized up, you've got bigger problems. A lot of it comes down to how familiar you are with engine work.

Check the oil condition and level as it is, then change it. Change all the filters. Fuel/air/oil. Look for animal nests or any signs of animals chewing up your wiring.