How would I enter something like this into a journal?

Sold merchandise on account to members $1,210, terms n/30. The merchandise sold had a cost of $760.
Thank you!!

You have two journal entries here.
1. to record the sale and your accounts will be; Accounts Receivable and Sales Revenue.

2. to record the cost of merchandise sold and your accounts will be; Cost of Goods Sold and Merchandise Inventory.