1994 Plymouth Acclaim Extremely high RPM - undriveable

I just bought this piece of *&^# car (but that's beside the point!) Which is currently undriveable due to a very high RPM at all times - in park, reverse, drive, etc. It is undriveable because I can barely engage the brake since the engine is revving so high. I drove it yesterday, and had to use both feet to engage the brake. It was scary. I've had one friend tell me it needs lubricant; another that something is disattached. Any ideas? I can't afford a mechanic.

Thank you so much.

Karen