GM forgot the dipstick and the plug. You really can't do much because it's "sealed". Check for a red spot under the car. Thats pretty much it.
Where Do I Check Transmission Fluid Level On Pontiac Sunfire , 1998?
,There are two dipsticks, one for oil, and one for transmission fluid. Pull each one out and look for the red colored fluid, that is the transmission, You want to have car idling and in park, before checking fluid level