Leneddy

So about two months ago, I bought my first Subaru. It's a 1995 Subaru impreza 1.8, I started working on it maybe 3 weekends ago. I'm finding a lot wrong with the car. I've already replaced all struts and springs, tie rods on the front passenger side, Both front lower ball joints. Earlier this week I heard a loud rattling noise under the car, I removed the exhaust shield from behind the headers to the cat. I found that the exhaust from the headers to the cat, was an inch and a quarter wide. After the cat to the tail was 3 1/2 inches, I tried recharging the A/C and the high side line was cut off (it sprayed refrigerant). Also there are some sensors missing, hoses unplugged or capped off. I'm currently trying to find a repair guide for this car, so far no luck.
I'm not sure how much I'd have to fix to get to run perfect, cause I would eventually like to try rally. I don't want to sell it but, it looks like it might happen!