I would say, "I want to learn English from you, so I want to copy your accent." Sometimes "mimic" means sound exactly like a certain person for laughs. For example, Margaret Cho mimics her mother: https://www.youtube.com/watch?v=8rzfUxzUsj8 You could also say Margaret Cho pretends to be like her mother. An idol when used in this way means a person--usually someone famous--not a thing. You could say, "That movie star is my idol."