is this right? My friend told me I could speak to her informally....i just want to know if this is a correct sentence. 한국어 교육을 위한, 고마워. (For teaching me Korean, thank you) Also, how would you say " I hope you like the gift I prepared for you."

안녕하세요! 안녕하세요! 메리 크리스마스. 제 이름은 Melissa입니다. 저는미국에서 왔어요. 사는 곳이 어디입니까? 우리가 좋은/친한 친구가 되었으면좋겠어.

What do I call her? I go to a Korean restaurant nearby regularly, but I do not know the owners name. Would it be appropriate to call her Aujumma? I am 34 years old and I am sure she is probably at least 40 years old. What are some things I can say to her when I eat there showing that I liked the food or that I will visit again soon? I always tell her hello and thank you in Korean.