How do I create second copy of the company file so I can test procedures to import data

You need to open a trial account and utilize the 3rd party tool to migrate (i.e copy/duplicate) the data. 

https://transactionpro.grsm.io/qbo

Use promo code 20PERCENTOFF at checkout, valid until April 30th, 2020

If you have to open a new QBO account, make sure to click the Buy button to get the discounted price for up to 3 months. If you purchase from the trial account, you have to pay the regular price.

https://quickbooks.grsm.io/Canada

https://quickbooks.grsm.io/Canada-fr