The colleges to avoid as an undecided student would be ones where the majors of possible interest are are difficult to declare or change into (e.g. require a high college GPA or competitive admission).
That list of colleges depends on what the majors of possible interest are. It is likely to be much larger if the majors of possible interest are computer science and nursing than if the majors of possible interest are physics and philosophy.
Additionally, some majors have fairly full curricula starting in the first semester. Nursing and most engineering majors do not leave much time to explore if one does not want to fall behind in those majors.