RE: First Time Planing!
OK, sounds like we have some "back to basics" issues here.
Putting the mast foot forward on a longboard, with a sliding mast track does indeed increase it's upwind ability as the rig is further forward from the centerboard, the lee rail can be "engaged" as completely as possible, and the board can be "railed" lee rail down here, to get the max. upwind lift from the centerboard.
You are on a higher performance short board without a center board.
SO.... all the stuff about the mast track forward kinda goes out the window.
Your Carve (at your skill level) is going to respond mostly to "foot steering".
By tipping the rockerline so the bottom shape takes you upwind (heel pressure or front foot pressure upwind of the centerline, putting the upwind rail lower than the leeward rail) you go upwind both in slogging (sub planing) and when the board is planing.
To steer your board downwind, you need to do the reverse and tip the board lee rail down with toe pressure on your back foot (right over the centerline of the board).
To avoid heading upwind you need to really pay attention when you uphaul to get the board truly in a "T" position with the rig right out in front of you, and the board nearly perfectly aligned "across the wind.
Then you need to step back BEFORE ADDING ANY POWER OR STEERING FORCES!
Once you have both feet behind the mast foot (front foot 4-6" behind the mast foot and 4-6" upwind of the centerline; back foot will be heel on the centerline with the toes to leeward and slightly pointed forward,
THEN you can think about adding some power.
If the board is still aligned in the "T" position, you can rotate your upper body (from the hips, as the feet need to stay where they are) about 5-10 deg. and your rig will power up and start you moving on a beam reach.
Once your board gains some speed (still on a beam reach), you can start to move your feet back slowly and progressively.
As you start to move back, begin to sheet the rig in a little to help increase your speed, but do not rake it back yet.
When you find your front foot just ahead of the front footstraps and your rear foot right over the centerline about midway between the front a rear straps, you can start to rake the rig back a little.
If the board turns upwind, you either have the rig raked back too far too soon, or you have weight on your front foot above the centerline of the board which is steering the board upwind on the rockerline.
If this happens, unrake the rig (standing it more upright) to get the turning upwind to stop.
Gain some more speed and get onto a plane.
Then think about hooking in to your harness.
Remember, the board has to be in the "T" position with the bottom flat to the water when you add power, or the boardf is going to start turning toward the rail that's lowered (leeward rail takes you downwind, upwind rail takes you upwind).
Your goal is to go straight forward and gain speed.
Once you have good speed and the board is planing, you can hook in, go for the footstraps, and continue to steer with your back foot.
Hope this helps,