I agree with Brandon, austinoccasions.
Backing up is always the best practice to safeguard your company file.
You can request from your bank a .qbo file format for your transactions. Then manually upload these to QuickBooks.
You might want to use the QuickBooks Mac 2019 trial to migrate your data in QuickBooks Online. I have prepared articles that can help you along the process.
Mention me if you need anything else.
