Auto Pilot ??!!

Lets face it we all love flying but sometimes youve just gotta have a rest.....so you turn on auto pilot. Ive tried many times but i just cant get it to work I set all of the dials and counters and hit the auto pilot switch but yet.........Nothing
My ambition in life it to be a long haul pilot but hey im 13 im not gonna do a 13 hour flight to Malyasia and back ?! so please help what am i doing wrong it just wont work the only thing it is capable of doing is wing leveler and then i still have to sit there holding the joystick making sure that the plane doesnt do a dive & crashes. (Please I need to know about Nav hold Because I am Very lazy!!)
thank you

