It would not be much of a challenge. I have a fondness for learning and Latin is something I have always desired to learn.
[He thinks for a moment] Perhaps our first meeting should be in a common place at the inn that is a crossroads for our worlds? It is likely far less dangerous than the world I live in and would allow you to become use to my appearance and I can prepare you for the manner of dress people, especially women, wear in the modern world.
I will not lie, I do believe witches exist though, to my knowledge, I have not yet met one. If I have, they did nothing to alert me to what they are.