Hello there, @Meg geisler.

I'd be glad to help you how to enter the hours worked by your employee for a specific customer and add a markup cost with it.

You can enter a Billable time in the Invoice transaction that you're going to send to your customer. Before that, you'll need to create a new service item to set the amount of the service rendered per hour. Then, create a timesheet, and enter the number of hours worked for the specific project or customer.

Once done, you can create an invoice and select the Enter Time/ Cost button. Check the service done accordingly and select OK. I've added some screenshots for additional reference:

To know more details about the process, you can check out this article: Tracking job costs in QuickBooks Desktop.

I've also included this article about the different kinds of reports you can use to get a better understanding of your business's financial status: Track your cash flow in QuickBooks Desktop.

If you have any other questions, please let me know in the comment section below. I'd be happy to lend a hand.