How do you set up a square loan in quick books and track it

For Loans you want to set up a Liability Acct.  If you think you may have multiple loans over the years, some people like to have a Loan Acct (which may already be in your Chart of Accts) and then create Sub Accts for each individual loan to keep them grouped together.  

So Create a Liability Acct called something like "Square Loan 2023" and make it a Sub Acct of Loans *IF* you want.  Also create another Expense Acct called "Loan Interest Paid."

When the money comes into your Bank Acct, link it to the Square Loan 2023 Acct.

When you make a payment, you'll want to make a Split Payment.  Let's say your monthly payment is $100 where $90 is Principal and $10 is Interest.   So in your Checking Acct you'll Split that $100 check to the Square Loan 2023 to bring down the Principal Owed (you would see the amount reduce by $90).  And the $10 Interest would go to the Loan Interest Paid to show that expense.