Help with walks 🙏

Hello everyone,

I have a lovely dog (most of the times), he is 5 years old now. My problem comes to walks with my son, when I was living back at the countryside the walks werent the biggest problem in the world, but I had to move out. Now I live in a big city and if he hears a loud noise or sees anyone/another dog he starts acting crazy, becomes extremely stressed out, tugs on the leash and wants to run home asap, so 90% of the time he doesn’t even want to leave the apartment building, people told me to not react so I try to show no emotion at all. His first ever walk here was actually fine which surprised me , we were able to take quite a long walk but now its getting worse and worse to the point where walks with my son arent enjoyable anymore, the only time I have a chance for a longer walk with him is between like 2-3 am when its the most quiet so I have been getting no sleep 🙁 I would love for him to be happy about taking longer walks again or be able to leave the apartment more easily because there is an amazing park next to us