1998 Cadillac Deville Cadillac idling and brakeing problem

I have a 1998 cadillac sedan deville that is idling high and low sporadically. It also feel;s like there is air in the brake lines or that maybe even the power brakes have failed at start up. Both of these problems happened at the exact same time. The RPM's are running high and low even in park. If I try and put the car in gear it takes off at a high rate of speed. What are your thoughts. I really appreciate your time. Thank you.