So you've just adopted a dog? That's awesome. But don't go dragging that dog around everywhere you go. Mazeltov needs to be settled in first (because you have named him Mazeltov. Go with it, it's a thing...). Adjusting to a new home can be extremely stressful for a dog and not all will settle immediately. But never fear, it will happen!
Imagine you've just been dumped by your family. Or maybe you lost your way and they can't find you. Now imagine you're in a cage, with people screaming next to you, hungry, scared, and alone. Now you've just been scooped away by strangers and put in a completely new environment... and it smells weird.
Congrats. You feel just like little Mazeltov. You're stressed.
Give your adopted dog time to adjust. Let him settle in, get used to your home and his new surroundings. Take him for walks, by all means, but avoid big crowded places such as dog parks for the first couple of weeks. Minimise his contact with other people and dogs.
You and your family need to bond with the newest member.
It's always best if your dog comes with some of his favourite toys (from foster care) but that's not always possible... some of you may have adopted straight from the Pound (yay you!). Familiar smells always help a dog settle quicker. Remember that you ultimately want your dog to adjust to your life and routine, so try not to change that too much. Let the dog observe it, do it, and eventually get used to it.
If you already have a dog and Mazeltov is your second (or third, or fourth... how big IS your pack?), then introduce them carefully. The best way I've found is to have them meet on neutral ground, somewhere where neither dog feels it's their territory. Taking them both for a walk at the same time (one on each side, or have two people walking them) gives them a sense of being part of a Pack and they will be less likely to have issues with each other.
Never leave the dogs alone together - at least, not for the first couple of weeks. You need to supervise them at ALL times. Eventually they will bond (and it will probably be sooner rather than later) but you really want to try and minimise conflict. And if you're not there to seperate them when conflict arises, then little tiffs can quickly escalate into big fights. Don't just think that because Mazeltov and Optimus Prime look like they're getting on means they can be left alone together.
Also remember that, if you've just adopted a dog straight from the Pound, you'll need to isolate him from the other dog, so as not to spread any potential sickness he may have (like Kennel Cough, for example).
Generally, you want to help Mazeltov settle in. Reassure him, give him love, cuddles, and attention. Make sure you observe his behaviour, as well as any other animals you may have in the household. Don't expose him to too much at once. Let him adjust.
And please, whatever you do, don't name him Mazeltov.
(I've got dibs!)