Our Goldie pup is six months old and We also have a seven year old GSD, they have great fun together and are a joy to own.
They are walked separately due to age and distance and have shorter walks together with my husband and myself, on our joint walks in the park we have no problems,I take pup in the car to the park and meet hubbie and GSD .
Our problems started Monday , pup had a vet appointment and when we arrived the vets they were not open so we waited outside,when they arrived they opened the metal shutters with a loud bang and clatter and pup was petrified and I had to man handle him in side to a place he hates any way.Afterwards I coundnt get him out of the place and it took me ages to get him back to the car.
I now can not walk him at all he refuses to go outside the door, we lifted him to the car and went to the park tried to coax him round with the other dog takes a few steps and then just refuses to move.have tried treats to coax him a few steps but he is not having any of it. He's fine as soon as we are back home playing and running around but loud noises reduce him to a quivering wreck when he is in the garden, a lorry went by this morning and he flew indoors an lay in his basket.
What would be the best way forward from this...

If you haven't been doing so already pups should be socialised around noises from the moment they are brought home, they need to be carried around (prior to the full inoculations even being done) in your arms along streets to hear sirens, cars, people, etc.

I live in the country and perhaps you also live in an area where there is not much town noise, but I always take puppies in my car to friends and family to walk around noisy places so that they are bomb proof for the future, it has to be done. :-)

When a pup is older and past the carrying stage and on lead, granted it is difficult to take to places like this if fearful as a pup/dog may panic and pull to get away or sit and refuse to move as yours has so for starters I would forget walking him in areas where he will get spooked I would suggest you take pup and sit for 20 mins or so every few days on a bench in a town, a village green outside a supermarket or simply sit in a town park on a bench or blanket, where you can control him on a short lead so that he can't run if spooked and he can't play up.

Take along treats to give him when he is calm. If he begins to panic ignore him and stay upbeat, never pet him or fuss him whilst he is showing fear, just chat to him calmly whilst looking at a mag or newspaper.

When he is more confident you can then begin to walk him past shops or when there is a siren going off, along with his normal walks for training and fun with your GSD.

Also if not already how about joining a good praise and reward training class and work towards the KC bronze, silver and gold, all good learning for pup and you and it will install confidence in your pup. :-)

Thanks Carrington, he does go to puppy training classes but at the moment that's a no go,prior to this episode he's been well socialised, loved going to classes loved everybody and everything and even now on his sit ins will still wag his tail at people and other dogs but will just not move.
I have been doing wrong as I've been talking to him and stroking him and trying to make soothing noises to encourage him to walk so I'm going to try the things you suggest going to take a chair down to our front gate to start with as that is about as far as I can get him. Thanks again for the different ideas.

Well, that is good to know, so he is not under socialised at all. :-)

The good news is then this will be far less work for you and everything will pop back into place far quicker than having to start from the very beginning. I dare say he will soon be back to normal this is probably just a case of him entering his second fear stage which is at about this time, when suddenly the world can look scary again.

All it needs is for you to just install in him as already said that everything is fine and all noises and things going on around him are perfectly normal and ignored by mum, so learnt to be ignored by him too.

Garden chair to the front gate is a great way to start. :-)