Leave of absence

Hi everyone. I need some help. Can anyone guide me please? My problem is that I couldn't submit my visa file at the Embassy because of no available visa appointments.

1. Can I take a leave of absence for the fall semester and re enroll for the spring semester?
2. I would need new COA for Spring semester. Will they provide it?
3. Would I need to pay the tuition again?
4. Will it affect my grade or academics?

If you have any idea please let me know.