Welcome aboard StayingPower!
With the first tutorial, keep an eye on your radio messages (press the m button to bring up a list of the latest). They have all the required steps you need to complete the mission.
Take your time with each training mission, and repeat them till you feel more confident. It's better to learn here than when you have a destroyer depthcharging you like no tomorrow.
Have a look ing the Newbie sticky at the top of the page for futher help and feel free to ask questions. We don't bite too bad here!
