Forget about trying to move in from the lunge - that's just going to confuse him (which it is) and unless you are experienced with drive lining or have someone to help you I would steer well away from that too
You should ideally be at a point around your horses shoulder - never get tempted to drag from in front - horses usually dislike being dragged and their reaction is to pull backwards and throw their head up.
I also use a long schooling whip to give a little tap behind the horses girth area to encourage forward movement. It will be a bit 'raggy' to start with but with practice gets better all the time. The horse should eventually just be 'looking' at you for your body cues and walk/trot/ halt when you do on a loose lead line with no verbal commands at all
This is one of those learning things that I use treats as a reward for