Welcome aboard, Andrew.
It's been a while since I played the American side, so I am not the best man to help you out.
There are definitely a lot of things to think about when you first start out as Captain of a sub! Leave it on auto-targeting and unlimited fuel until you get more experience and so can concentrate on other things. You can always change the settings after you have got used to handling the boat. The most important thing is to have fun!
Good luck and happy hunting
