Hi . He is soo cute. Even though I have had dogs for all of my life, when we got our current dog, Belle, I was stumped at first. She was a rescue and had been in the kennels for most of her life - she was two when we got her and she had not been well socialised so was very aggressive toward other dogs. I almost sent her back but realised that she just needed our love. Six years on, she is now one of the best behaved dogs you could ever wish and boy, does she make us laugh!
So, my best advice is: plenty of love, SOCIALISATION with other dogs and people and as said above, reward based training. If he misbehaves, ignore him and he will soon understand that he gets the best of your attention when he is good. Oh yes, and lots of love!!
Good luck and let us know how you get on.