How should I list the conferences and courses I attend as an undergrad student to my CV?
Yes, I would suggest you include these in the CV for a graduate application.  It probably won't make a huge difference in admissions, but it is evidence that you are interested and involved in the research community in your field.

You can list them in any way that seems appropriate; there's no strict standard format for a CV.  You probably have sections for "Education" and "Work experience" and maybe "Publications"; make a similar section entitled "Conferences attended" or "Conference participation" or something like that.  Include the title, date and location of each conference, and maybe a short sentence discussing the scope of the meeting and your role.

(As discussed in the question you linked: later in your career, you will probably want to take this section out.)