What is a ECM and are they alot? and where can I get one because the camaro I bought is missing a ECM from the computer.

 

The ECM IS the computer. If the computer is there and something is missing from it, that would likely be the Calpack (prom chip etc in 1 package) You'd need to know the engine size and type (TPI, TBI, CCcarb) to get a new one. Then you'd need to hope the GM parts people order the right one for you.