Hi Juliana.
I appreciate for sharing your concern in this thread. I'm here to help you with QuickBooks and the activation process.
To get started, may I know where you've purchased your QuickBooks Desktop (QBDT) Pro 2012? This way, we can review this further and figure out how you can activate and start using QuickBooks.
It would be best to have the supported versions of QuickBooks (QBDT 2021, 2020, 2019) to avail of the latest features and other Intuit services. The good news is, Intuit still allows users to download the old version of QuickBooks. 
For additional tips about downloading and installing QBDT, I recommend opening these links:
Moreover, I would also recommend connecting with our Support Team during their business hours. In that way, a live representative can check your account securely. To contact support:
- Open this link: https://help.quickbooks.intuit.com/en_US/contact.
- Click on QuickBooks Desktop.
- Set the product and edition, then enter your question, then click on Continue.
- Choose a way to connect with Support.
For your future tips, while working with QuickBooks, I also suggest opening the topics from our help articles.
If you need additional help with activating QuickBooks, please notify me by adding a comment below. I'm always here to help. Have a good one!
