Where and how do I file interest paid on a small business loan? Should I have received a specific form from my bank?

You may or may not receive a notice from your bank of the total interest paid during 2018, but you should be able to find this amount on a recent loan statement from the bank.  If not, contact them to give you the amount.

You can record the interest expense from your business loan on your business tax return in the section titled "Common Business Expense" and then scroll down to Interest Expense and enter the amount of interest expense for 2018 on the line item.  See steps below.

To be brought to the section in TurboTax Business to enter your interest expense:

1. Select the Federal Taxes tab at the top of the screen,
   
2. Then select the Deductions tab. 
   
3. From there scroll down to Business Expenses and then select Common Business Expenses.  See sample screenshot attached. 
   
4. On the next screen, scroll down to Interest Expense and enter the amount for 2018.  See second sample screenshot.