It can't hurt to go to the interview. Even if you decide not to take the job, the process of interviewing for it and evaluating the job will be a good learning experience.
Being torn is natural. We have all felt that way at times. Back in the dark ages, when I was a student ... I was accepted for the "perfect" externship for me. However, I also got a scholarship
to study political science in England. As the Dean of my nursing school told me, I had the rest of my life to learn how to be a nurse. My scholarship was a once-in-a-lifetime opportunity. I went to England. I sometimes wonder "what if ...," but I have never reqreted that decision. Yes, I was a bit behind some of my classmates who had done externships, but I survived.
Let us know how your interview goes.