Puppy scared in the streets

Hello everyone 😊

I brought my sweet Cairn Terrier puppy home 12 days ago and he's a sweet puppy. He is 12 weeks. He's doing well at home with our two cats and our two kids. But we cannot for the love of me start potty training as he is scared of the streets. Our neighbourhood is very noisy, lots of motorbikes, trucks even at night, schools and he refuses to go outside, starts shaking also. We called the man we got him from and he told us to force him since he will have no other choice but to live here. I was really angry at this piece of advice I refuse to force my puppy into doing anything.

The only good thing is that he looooves going to the park ! He thrives ! He explores, sniffes, relax. We meet other dogs and it goes really really well, we meet friendly people and he likes them. But he never pees or poops in the park either …

We tried giving him treats when in the streets but he does not accept them. He's too stressed.

Any tips ? 😊

Have a lovely day