did you get an authorization email?
is your account being managed by an educational institution? or did you download the evaluation copy?
Some details in this regard might point you in the right direction.
After installing ArcGIS Pro, you need to login to ArcGIS Online using your trial account credentials, and configure ArcGIS Pro license to your named user. Manage licenses—ArcGIS Online Help | ArcGIS
Hi Taylor.
Since your message is posted in the "Career and Technical Education" project (a part of the Esri K12 Schools program), I'll assume that you are a classroom instructor.
Please review and request for your free software for school instruction at: Schools Mapping Software Bundle for Grades K-12 | Esri
After making the request, we will reach out to you via email. This will include an acknowledgement but also information about how to acquire and activate your school's new software. If you have further questions, feel free to email schools@esri.com
Thank you,
Tom