How long do I have to enter the country with a new F1?

So I have to take the first semester online because due to embassies being closed and the travel bans, I cannot make it in time to join in person classes (not even with an emergency appointment). I will have to wait until January to travel.
Classes will begin the first week of January and the soonest I can travel with my I20 is December 11th.
Before I try to reschedule my visa appointment for an earlier date I wanted to ask if anyone here knows if I have a limited amount of time to enter the country after I get it. For example: I have to travel within 30 days of the visa being issued or I cannot have the appointment earlier than a month before I can travel etc.
Thank you!!!!