I wouldnt lead him anywhere on a road until you know you are in control, so lots of in hand and ground work for starters. If you do decide to take him out, then always put the bridle on for more control, some people use a chifney but you either like them or hate them. I would practise perhaps having someone lead your horse around the field and then you go behind and keep practising. If that was me, I would have a mate lead my horse around the field/yard , I would take the youngster and put a bridle on (he does wear a bit?) then, we would go nice and slowly, everytime he pulled, rushed or jogged, I would make him stop and then back up for about 8 paces then, start again in a walk, as horses hate being made to go backwards, he will then start to listen to you, I would keep doing this until he behaved himself, then you can start going out. If the horse is very strong, a chifney while out will help but, to be honest whatever you put him in, if he decides to 'take off' you would never be able to hold him, hence the ground work is so important, lots of 'NO' everytime he pulls with excitment and then make him back up and start again. Kelly Marks has a very good book out called 'perfect manners' and there is a whole section in it with regards to leading and ground work, your horse is still a baby.