In addition to your professor’s office hours, the University provides a few options for extra help.
The University Learning Center offers a variety of services, including drop-in tutoring and review sessions, all done via Zoom. More information and schedules can be found here: https://www.nyu.edu/students/academic-services/undergraduate-advisement/academic-resource-center/tutoring-and-learning.html
The Department of Mathematics also offers drop-in tutoring, all done via Zoom. More information and schedule can be found here: https://math.nyu.edu/dynamic/undergrad/tutoring/