You are the first to learn the country's language, to me. I feel glad and I intend that I will teach you everything you want to know the best. I promise
You are the first person willing to learn the language of the country I was so happy, and I have determined that I will teach you everything. You want to know the best, I promise.
You are the first person intended to learn the language of my country, I feel, and I determined that I will teach you everything you know best. I promise.