So I clicked "I accept. Proceed with account creation." and it says:
Your registration E-Mail has been dispatched to (Your E-Mail Here).
Please give it a few moments and check your inbox, then follow the instructions within.
Be sure to open the registration link from the E-Mail in the same web browser you used to sign up for your new Fur Affinity account.
Note: Your account request will hold your username for 24 hours. If you do not confirm the request in this time it will become available again.