The dipstick should be on the left side (driver side) of the engine compartment in the back near the firewall. You need to look for a cap with an arrow on it.
To open or remove the dipstick you need to push the front of the cap forward and then pull up to remove the stick.
You can also look undeneath at the front of the pan (sump) for the transmission.
You should see a tube with a large nut that attaches the tube to the pan.
Follow the tube up to find dipstick.