General Fix Ups
 

I'm not mechanically inclined, but I'm wanting to learn. I bought an 87 Xlt Lariat with the intention of making sure it's a reliable driver and figuring out how to make it that way through trial and (hopefully minimal) error. Hands on, that sounds better. I think the truck has sat for a while with just intermittent driving and the gas gauge doesn't work. Having never bought an old vehicle that will need some work, what are some tasks that I need to do that are first and foremost? I'm going to change the oil, I put some fas and soafoam in, the coolant was empty so that'll be filled. The important electronics (lights, speedometer, wipers, ac, doors and locks) work, but not the radio speakers. Any suggestions I will research further, but if you kind folks can point me in the right direction, I'd appreciate the help. I'm not sure as to what sort of issues an idle old truck can have, or what parts generally need cleaned/ upgraded/ changed for a vehicle such as this. Thanks in advance to the help

It is an rwd 302 automatic

From past experience I'd check the brakes as well as "all" the brake hard and rubber both for heavy rust ( leak potential) and cracks in the rubber lines for starters and dont forget the emergency brake cables.
Then onto the rotors for heavy rust between the discs.... all potential problems of a setting truck as well as one thats driven.
B4 taking anything apart your not sure of take pics and place parts in order they were removed, then reverse and ck pics in problem areas and one thing at a time.
Goid Luck nd welcome to the world of fixables.