mmmm kay, I need a little help

Alright, I have a 1994 VW Jetta GL Sedan.
Now, I like this car. It's cute, gets good gas milage and the outside and inside are all lookin good. I bought this car quite a while ago (so no chance of returning it).
No problems until now. :(  
The check engine light came on.. AND the oil light came and and now the temp light is on..
I took it to a mechanic. He told me he didn't have a scanner for that year of Jetta so he couldn't help me with the check engine light. He did check the oil and the oil level and pressure he said were fine, so he's not sure why the oil light is on. The temp light was not on however when I took the car to him.
It just came on the other day. It's off and on when I drive. The temp gauge looks fine. It's always right in the middle, never goes over the middle. So I'm assuming that means my engine isn't overheating. (Hopefully lol)
The check engine light is on here and there.. The car runs sluggish when the engine light is on.. the mechanic did say he felt the car had been in a wreck before.. Some hoses were connected to/into places that they weren't supposed to be connected, and the heater core is broken. I checked carfax and there was no record of a wreck (although that doesn't mean there wasn't one.. Someone probably just didn't report if and tried fixing it themselves.. That's what he said it looked like to him..) The oil light is pretty much on all the time..
Any suggestions? (Other than getting a new car lol I can't afford one right now..)
Thanks!