You don’t do anything regarding course selection when applying to the school.
After you are admitted and choose to enroll, the school will look at your AP scores, CLEP scores, dual enrollments, transfer credits, etc., and tell you for which courses you have been given credit and/or advanced placement.
A “typical” university will have defined plans of study for each major, and a “typical” freshman course schedule based on school/major. This “typical” can vary widely - Purdue engineering admits students directly to First Year Engineering which has a very well defined set of first year courses. LACs seem to be much looser, from my reading, with categories of courses and suggestions.
Either way, you will usually be assigned an advisor who will help review course selection, credit, placement, etc., and get you to a first semester schedule, after which you will register for classes (specific days/times/instructors). At Purdue, students get a specific time-slot to register and classes fill up quickly. Students may need to shift specific class dates/times to avoid overlap or even change courses (my D took 2nd semester Chem as 1st semester Physics was full).
This is all completed weeks before the semester starts and is repeated every semester.
That’s a “general” approach as I’ve seen it - I’m sure there are schools that vary.