To answer your question on admissions chance…it depends on the school. Some schools don’t allow you to declare a major until 2nd year. Others ask your intentions during admission. You’ll need to research each of your target schools to determine the answer. More info: http://www.collegeconfidential.com/dean/000062/
Common majors can be deduced by examining the Degrees Conferred, which is included in the Common Data Set each school publishes. I haven’t seen a good site to easily explore this data set, but a search for + “degrees conferred” will likely find results. Example:
https://registrar.stanford.edu/everyone/degrees-conferred/degrees-conferred-2015-16#bachelors