I'm going to give you some advice, being younger [although quite a bit older than you], and having restored multiple vehicles.
Make sure the vehicle is mechanically sound before you start 'pimping' out your car. A lot of people over look that step, and just right into stereo equip and customizing.
You also need to realize, that these car's aren't something you can sink 10,000$ into and get it back. Most car's you can't, although [knock on wood] I've made money off every car I've fixed up so far.
I feel like a 'pimped' out Eagle would actually depreciate the value of the car. My advice would be any modifications that you make, keep the original items so you could return it to stock if you end up selling it.
If you plan to hold on to this car for a LONG time, I'd slowly restore it, but keep in mind you'll be sinking more than the car's value into it, to get it into show condition [depending on what you start with.] Look around online and you'll see tons of car's that people have customized and sunk 20-30,000$ into and they'll be lucky to get 10K for the car.
Most people who customize/restore car's realize this, but I just wanted to give you a heads up first and make sure you know that.
Other than that, welcome to the hobby. You'll start to learn what you like and what you don't like about certain cars, and you can add to yours and make it personalized to you. Don't worry about what other people think of it, as long as you like it!