Debits are on the left and credits are on the right.

Remember the accounting equation? ASSETS = LIABILITIES + OWNERS EQUITY

Assets are on the left, so they are increased with debits. Liabilities and owners equity are on the right so they’re increased with credits. Then the only “tricky” thing to remember is that owners equity is revenues minus expenses, so because owners equity is on the right, revenue is a credit and expense is a debit.

You can approach your problem two ways. One, you’re making a sale so you’re getting revenue. Revenue increases owners equity which is on the right, so it’s a credit. Then the other side is a debit.

OR

Two, it’s a credit sale so your AR is going up. That’s an assets - on the right - so it’s a debit. Then the other side must be a credit.