When does he stare at you? When he wants something or when you are doing something he dislikes or some other time? It could just be how he looks or it could be him trying to tell you something (either begging or warning). What does the rest of his body do when he stares? Is he tense/frozen in place? Do his eyes move at all? Do the whites of his eyes show (whale eye)?
Why don't you also start building a relationship with him where he has to learn respect but also trust. Try clicker training, it is really a great way to train and you teach dogs by telling them what they are doing right whether it be them sitting when you are trying to teach them to sit or even them NOT doing something like not barking when someone comes to the door even though they usually do bark when that happens. Clicker training allows for you to have a non-confrontational training relationship with your dog. Instead of always telling your dog he is wrong and punishing him or correcting him you can ignore or prevent the bad behaviors and reward the good ones until he is choosing the good ones all the time. Or take a bad behavior (licking guests constantly) and teach him, through clicker training, to do something else that prevents him from performing the bad behavior (holding a toy in his mouth when guests come over until he calms down makes it so he can't lick).
It's just a suggestion but after reading some books (I'm in the middle of Click to Calm by Emma Parsons) I am in love with clicker training and recommend it to everyone.
Right now I would not be thinking your dog is out to get you or that you need to be dominating him or anything like that. Just remember you don't know what he's been through (unless you do lol) or what might be threatening or scary to him. Focus on building his trust and start training with him in a positive manner so he learns how to listen and respect you and knows the rules of your house, knowing the rules will help him feel more secure as there is no guess work for him, he does not have to try things out and see if he was wrong, you tell him what to do from the beginning through marking every good choice he makes and preventing him from making bad choices (by dog proofing and marking good behavior such as behaving well at the front door when guests come, even if he was not showing the bad behavior (jumping, barking etc.) in the first place, he needs to know he is doing it right and does not need to experiment further).
Hope this helps! How is he fitting in? Does he enjoy being around you or is he nervous at all? I'd love to see some pictures of him
