The entire system is shown on this RockAuto link
If you are going to replace the cat, a new one is $200 or so and the entire rest of the exhaust is another $237. The cat is bolted at the front and looks like a slip-fit a the rear. Given the age of the car, I’d replace it ALL, especially if you are doing it yourself. It will be rusty, it will fight you to the near-death at the slip joint, so just do it all.
For $237 you get 2 mufflers, and the mid-pipe. That’s a deal. The only issue will be the bolts or studs at the front of the cat. If bolts - easy, cut them off with a friction wheel or break them with a breaker bar and socket and replace them. Studs - go easy and use lots of penetrating oil. Impact wrench helps pound it off but don’t set it too high or the stud will break. Then you’ve gotta drill it out. Did I scare you or confuse you yet? If I haven’t, go ahead and DIY it. You will need a a way to lift the car fairly high to get everything out.