Aim is purely about the club face aiming directly towards your target when placed behind the ball. Use the leading edge or bottom groove at a right angle to your target line.
Alignment is your body in relation to the aim line or ‘ball to target line’. In an ideal world your feet, knees, hips and shoulders need to be parallel to the ball to target line, not always possible and indeed if you look at the best players in the world this is not always the case, the one consistent and most important parallel alignment are the shoulders. If you draw a line across these parts of your body they will all point slightly left of your target (right handed golfer), parallel to ball to target line. Imagine tram tracks, you are standing on one line and the ball and club head are on the other.
The common mistake I see is golfers aiming their shoulders at the target and not parallel to it.
The ball position progressively moves forward as the club gets longer in length, your shortest club is in the centre of your feet, the driver s opposite the inside of your front foot.
To know you are roughly the correct distance away from the ball with each club I suggest a simple routine to check-
If you are too far away it will miss your knee and drop lower, if you are too close it will rest way above your knee cap. Adjust your distance from the ball until you are in the correct position then place your right hand back on the grip and set the club behind the ball again. Important at this stage to make sure your heel to toe balance is central.