Hey! I’m a current junior, and I took AP Spanish Language last year in addition to some ‘heavy’ courses like AP Bio, and I really enjoyed it!
Spanish is not something that would be particularly helpful to me as a prospective neuro major, but, like you, my Spanish teacher told me to take it after my freshman year. I found that it was a great class to take as a break from some of the other classes and activities I was involved in.
I did have an excellent teacher who did not let anyone in her class really get a bad grade, so I guess it comes down to what type of teacher you have. But I would encourage it!
It’s also good to show colleges interest in a non-STEM field for a more holistic transcript instead of one wholly focused on STEM classes.
Good luck!!!