The last add/drop period before final registration (a.k.a. shopping period) will be August 31. As long as you don't have any holds, you should be able to register, add, and drop courses during this period at the assigned times listed in your Barnard Portal and/or Student Planning.
If this fall is your last semester, you may not need to take 12 credits.
If you need a few extra credits to stay on track to graduate, see this recent list of 1-2-credit courses.
You can use Vergil to search for open classes.
You can use SSOL to view your position on a waitlist.
You cannot register for more than 19 credits at this stage. You may be able to get adviser permission for more than 19 credits during the final registration period, September 3-13.
Final Registration Deadline is September 13, 2024.