Hi Engineering Student,
Well, you are probably already taking math and science courses.
The best introduction to becoming a scientist is to find a scientific institution where you can get a summer job or internship and work with a scientist on a research project.
I think all of the NASA centers have such programs and probably most of the National Labs...Check out some web sites of place near you and look for student and/or summer programs.
I've mentored a bunch of summer students in my career and we've always had a lot of fun and learned a lot.
Good luck
Paulett