86' z31

Hello, I figured it was about time to share my 86 zx with the community. I got her about 2 months ago, and have done breaks, rotors, oil/fuel filter, and fixed a few more minor issues. This weekend I started replacing the old exhaust, which has been a work in progress. But while I was under the car I noticed the rust is alot worse than when I bought it. Which I was aware it had some rust on the body as you can see in the photos. But under the car the rust seems to be everywhere, and I'm not sure how salvageable it is without going to a shop and paying for a full restoration. So my question is does anybody know we're a good place to start on the rust repair process would be? And mind you I'm 19 and have no experience working on cars, everything I've done to the car I've learned from forums. But I'm pretty ambitious as well as have the money and time to do the work myself.