Thanks for visiting the Community, @oldnotdead.

I’m here to walk you through the steps in recording the security deposit and 1st-month rent you received from your tenant.

First, let’s create an item for the security deposit and 1st-month rent, then link them to a Liability account. Here’s how:
1.    Go to List from the top menu and select Item List.
2.    On the Item List window, click Item, then New.
3.    Select Service on the Type drop-down.
4.    Enter the Item name and fill in other necessary fields.
5.    On the Account drop-down, select a Liability account.
6.    Hit OK to save the item.
7.    Follow the same steps to create an item for 1st-month rent.

Check out this article for more information: Add, Edit, and Delete items.

Once done creating the items, record the payment by using a sales receipt. Here’s how:
1.    Go to Customers menu and select Enter Sales Receipts.
2.    Select the tenant on the Customer: Job drop-down. 
3.    Fill in the relevant information at the top of the form like the Date and Sale No.
4.    On the first and second line item, choose the security deposit and the 1st-month rent items respectively.
5.    Enter the amounts on each item.
6.    Hit Save & Close.

You may take a look at this article for reference: Create sales receipts.

That should answer your question for today. Please let me know if you need anything else, I’m always here to help. Take care and have a great day!