Does there an appropriate time for me to get my money back from Cash app?

No, not any fixed time. You are allowed to make a request for a refund till 60 days after making a payment. So, within these limited days, you can apply to get my money back from Cash app. For this, need to select that payment and make a request for a refund or call that person to ask for a refund. https://www.numbersfor-support.com/cash-app-customer-service-phone-number/