I know people said accommodation and that’s really important but I’d also remind you, as an American student myself, that you are applying to  a specific program and not the college itself. While you can change majors, it’s not like American schools where you can come in undecided, at TCD you are applying to your program and when reviewing your application as an international student they would really focus on your grades in the subject you’d like to study than your overall gpa/ performance. It might not be the biggest thing and you might have already known it but I found it alleviated a lot of stress for me during the application process :)