Hello there, finance144.
What specific error message did you get when trying to proceed so I can walk you through the correct steps on how to get rid of it. We can also verify if the unexpected behavior is caused by a browser-related issue.
Try signing up using a private browser and then follow the onscreen instructions on how to sign up. You can use these keyboard shortcuts to open one:
If you're able to successfully signed up for QuickBooks Online, you can switch back to the main browser and clear the cache. You might also want to use other browsers to isolate these kinds of issues.
Let me know how this works. Take care and have a great day!