Oil leak, Wiring Harness, ABS and speed sensors not on speaking terms and code P0500

New to the forum. Just getting into car work, mods and maintenance on my beloved 4Runner now that I am not a poor student. Decided to take in my '01 SR5 after letting some problems go for a while due to a cash flow problem. Just wanted to get some info on traps to avoid from mechanics and an idea of whether or not this is salvageable. This was my first car and I have routinely told my wife that even after we get money for a new car I would like to keep driving this... I mean why get a car that looks less beautiful and costs more money?

This is the result of the initial diagnostics:
Multiple oil severe oil leaks including but not limited to the rear gasket
Break in the engine wiring harness
No communication between the ABS and the Vehicle wheel speed sensors (speedometer not working)
Check engine light is on returning P0500 code

I guess any knowledge about what could be going on would be helpful and any insight into the extent of the damage/ what a fix might entail

Broke the rules with the first post. Did some searching and found some info in the forum about the P0500 issue and the associated dash lights. Thanks for answering some questions before I even asked.

 

Honestly changing the gasket isn’t all that bad. There’s some videos out there on YouTube showing you how. It’s actually one of the first things I did on mine when I got it 3-4 weeks ago and I’m a beginner myself.

 

Oil leaks are going to be the valve cover gaskets (easy), oil cooler gasket (easy)...rear main seal (a total bitch). My oil leaks from the valve covers were so bad...I suspected my main seal...but I am going to wait and see if there is still a leak.

You'll have to track down and fix each of the others.

 

Update from the dealership. Looks like the last mechanic to change my calipers didn't seal it correctly so I was leaking brake fluid. This would not have been a problem if my ECU was functional and I didnt already have every light up on the dash (no warning about low fluid). Radiator isn't looking hot but doesn't need replacing right this second. The bushing on the rack and pinion has basically split in two. As mentioned there is also oil leaking from everywhere. I am going to attempt my first bit of car maintenance above changing my own oil and replace the valve cover gaskets and camshaft plugs. Wish me luck. Will update if anyone is interested.

Also keeping an eye out for an ECU. Haven't found any Gen3's in a junkyards near me, but gonna keep an eye out (not that I'm wishing ill will on anyone's 4Runner).