I don't think neighbour and friends are the same, like in English(well you can be a friend with your neighbour :) ). Your teacher is not wrong but that might be a bit too long...(Japanese people tend to say things as short as they can) If you say "a new friend" in Japanese, it would become; 新しい友達 If it's a new neighbour, you would say; 新しいご近所さん or 新しく近所になった人 I hope this would help :)

Hi Carl. That phrase that your teacher said sounds a bit odd. I would say, 新しいご近所さん、新しく近所に来た人 or something like that. And I would say " I have a new friend", 新しい友だちができました、新しく友だちになりました or so, although it depends on the contexts. Is it an answer of your question?