The next step will be to walk him in a safe quiet area and keep him in a very structured heel correcting him for even the slightest deviation from heel position. When you’re ready you can work at a significant distance from his triggers and correct the very first sign of interest in the dog/person/cat/squirrel whatever he reacts to. Generally the first sign will be perking up of ears or wrinkling of his forehead. Correct that stuff firmly and maintain a calm energy yourself. Advocate for him by creating space and not putting too much pressure on him. This may mean crossing the street to give a wide birth to the dog behind the fence, or walking down another street to keep distance from an approaching person. Over time you can close the gap and will be able to walk right past what used to trigger him.
That’s where the repeated exposure comes in. Once you can pass by old triggers they will fade away if he continues to experience them routinely. Never be embarrassed by your dog’s behavior, just get to work on stopping the bad stuff. You will be able to quit the night walking and come into the light!