Hi there, MakingCentsBookkeeping. Thanks for reaching out to the Community.
You can set up a liability account to record a loan and its payments. This will also track what's owed.
Here's how:
1. Use your Gear (⚙️) icon and choose Chart of Accounts.
2. Click New.
3. In the Account Type ▼ drop-down, pick Long Term Liabilities or Other Current Liabilities.
4. From your Detail Type ▼ menu, hit Notes Payable.
5. Give the account a relevant name.
6. Specify when your client wants to start tracking their money using the ▼ drop-down menu.
- Choose Today if the account you're tracking is new as of today. In your Account Balance field, enter its current balance.
- Pick Other if this account was started on another date. In your Select a date field, input the date you want to initiate tracking. Use your Account Balance field to specify the balance.

7. Enter the full loan amount as a negative number.
8. Select Save and close.
Once your liability account is configured properly, you can proceed with recording the money and repayments.
I've included a couple resources about working with loans that may come in handy moving forward:
Please feel more than welcome in posting a reply if there's any other questions. Have a wonderful day!