I have a 95 chevy monte carlo,when I turn the vehicle on, it idles very high. What do I do to fix this problem? The rpm needle goes as high as 3 it only drops when I shift the gears but when I shift the gears the vehicle takes off as soon as I release the brake pedal.

How do I fix this problem?

Adjust the throttle cable, where it goes into the throttle body. Back off the outside nut, until the correct idle rpm is achieved, and then "lock" both nuts.

Clean the throttle plates, a throttle plate stuck slightly open do to a build up of gunk will cause it to idle high

Clean the passages for the idle air control valve (IACV) while the engine is idling warmed up.
You may have to work the throttle to keep the engine running while cleaning.
If cleaning doesn't help, you may need to replace the IACV with a new one. The new one will self-learn once installed.