When i start the car it goes to about 1200 rpms but then drops to a steady 1000. normal?

what year and engine?
my 96' with the L67 idles at around 650/700rpm when warmed up. that is where it should be. if your is idling high then you may want to clean your intake/TB/IAC etc.

Yes I would have to agree with 96riviera18, My 92 Riviera 3.8L also idles around 700.

My 95 Riviera s/c 3.8L also idles at about 1000 rpm.
I do not know if it is normal.

I don't think 1000 RPM sounds to high. Remember their is not correct value, except what the PCM is commanding. If you have access to a Scan tool, look at the command RPM and the actual in the data list. If they ae within 75 rpm or so, you are good.

When i start the car it goes to about 1200 rpms but then drops to a steady 1000. normal?

the car idles first a little higher until it warms up. I dont think mine idles at 700 though (its a 96). I think its about 900.

your engine is a series 1 though so it might not be the same as series 2 (96'-99')

my 95 idles at about 1000 until it runs for a fewminutes, then it drops to about 600 or so. also when i have the A/c running it tends to run a about 700 warmed up.

750 solid when warm.