I’m a junior, still en route to continuing a major in accounting.
Thinking of taking a second major either marketing or entrepreneurship.
What’s best if one wants to open & run a new business permanently in the future after working (gaining some experiences)?
I vote for entrepreneurship.
Are you planning to become a CPA?
Both will help. One thing you may also want to consider is whether one or more of your accounting courses can be double-dipped for marketing or entrepreneurship requirements.
Both are fine. It is not necessary to have a double major, so IMO the most important thing is to take the courses you feel will be most helpful to you.
I agree that both can be fine, but the entrepreneurship should relate more to starting a new business. Only do the second major if you can do it without extra semesters at school. Better to get out and work. After working you could also go back later for an MBA and get entrepreneurship through that path.