Especially when you first meet an instructor or tutor, err on the side of formality. The person will volunteer if you may call them something else. (Also, as Johanna and Fomite mention, pay close attention to how they introduce themselves and how they sign emails to you.) If you have an academic advisor or a professor you feel comfortable approaching outside of class, you may be able to ask them about the appropriate forms of address.
After I introduced myself and signed all emails as "Dr. [Last Name]", a student sent me an email addressed to "Miss [Misspelled First Name]." I did not think it useful in that situation to correct the student, but it did not convey respect. I was not offended, per se, but I was annoyed that the student had not paid attention enough to know how to address me; while it did not affect the student's grade, it might have changed my perception if I were writing a letter of recommendation. I still am amused by how wrong the student got this, and I still wonder whether they were trying to get it as wrong as possible. (Personally, I find "Miss [First Name]" less respectful than just "[First Name]".)
If a student called me "Miss" or "Miss [Last Name]" or "Ma'am" in person, I would dislike that and probably politely say, "Please, call me Dr. [Last Name] or Professor [Last Name]." (My title is not "Professor," so I was originally hesitant to usurp that title, but it seems to be the culture here.)
There's a lot of politics around status in this question. It looks petty to squabble or correct someone over mode of address. However, many students act disrespectfully toward instructors who appear younger, especially if they are female. Not using forms of address that are respectful within your culture (for instance, that acknowledge role as a teacher and/or academic degree) can signal that the student might later challenge the instructor's authority in other ways.
In the U.S., you can respectfully address someone as "Professor [Last Name]," "Doctor [Last Name]," "Professor," or "Doctor." Often "Professor" is used based on the person being one's teacher, whether or not their job title includes "professor" and whether or not they have a doctorate. In other systems (I believe the UK?), there may be a lot of status attached to being able to call someone "Professor" beyond mere "Doctor," so perhaps calling the lecturer "Doctor" or "Doctor [Last Name]" is the safest approach.