See my tutorial about the takeoff, may be you get some clues, minute 13:
But to takeoff when you are in the runway you have to be sure you are line up with the runway heading, look both side left and right of the runway, with the help of the track ir you can move your head to the left or right to check if you are lined up, and ASAP you have enough speed try to raise your tail until get the takeoff speed
You can try the two ways to takeoff, raising the tail with low speed until get takeoff speed, or keep the 3 wheels on the ground... with the first one you will be able to see forward, with the other one you need one mechanic hand out the wing telling you the direction xD