The box should be big enough for your dog to turn around in. The sides should be low enough that your dog can enter by himself, but high enough to stop your dog from peeing out of the box if he lifts his leg. If you buy a box with a hood, consider cutting the top off to make the box easier for your dog to use and for you to clean.
Don’t place the box near your dog’s food and water, as dogs will not eliminate where they eat. Be aware that dogs have a tendency to dig in their box, especially at first. Place it so that any litter thrown out during digging will not cause too much of a mess.
A puppy can usually hold his pee for the same number of hours as his age in months during the day. Puppies can hold their pee longer at night. A 4 month old puppy should be able to make it through the night
