Where can i enter cash sales without having to issue an invoice?

Hi userjessmaiorano, 

Welcome to the Community! QuickBooks Online makes makes managing your business both flexible and easy. I can explain how to record your cash sales in a way other than issuing an invoice. 

QuickBooks Online allows you to record your sales as either Invoices or Sales Receipts. Invoices are used when the customer will be paying for the goods or services at a later date, while sales receipts are used when payment is received at the time of the goods or services being delivered. Here's how you can use a sales receipt to record your cash sale:

• Navigate to the + New button to the top left, then select Sales receipt. 
• Select the customer's name from the Customer dropdown menu, then enter the date. 
• In the Payment method dropdown menu, select Cash, then select which account to apply the balance to in the Deposit to dropdown menu. (Note: If you'll be depositing this cash to the bank at a later date, you'll want to select the undeposited funds account. You can learn more about this process in our Community article Deposit payments into the Undeposited Funds account in QuickBooks Online)
• Enter the line item information, the amounts and tax codes.
• Once you're finished, you can click Save and close or Save and send to email a copy of the sales receipt to the customer. 

Your cash sale will then be recorded to your QuickBooks Online company. You can learn more about using sales receipts in this Community article: Create and send sales receipts in QuickBooks Online

If there's anything else I can assist you with please let me know!