Re titles, in USA its very common they call the leader "SenseiKruSir" for prof. ie professor.
If you have in your country some usual everyday title for a teacher, you can use this instead, if you so want.
So for example, here in Sweden male teachers in children school are called for magister. Nowadays it have no connotations any longer its really an academic title... Its just what you call all male teachers. Its of course worse for female teachers - they are called for miss.... So it is nowadays a title of sorts this too...Even if once upon a time miss and magister were a mark the male teachers hold a higher status and also a higher salary - because they were male... Im digressing, but you see the picture: Its formal titles but none of them bears much formal weigh.
If the teacher by any reason dont want to be called by the first name, they use this title. But its common the swedish teachers use their first name.
YOU can of course use your first name if you are comfortable with it. Its usually the best, but the risk is some few students may misuse the privilege... Just be prepared for it...
Good luck!