If you have one employee that you pay weekly is it possible to lodge once a month to make it easier?

No, pay events should be sent after every pay run (from the day you complete a pay run until the day you process the pay)

Here's an article that covers the process for lodging a pay event.  

https://quickbooks.intuit.com/community/Payroll-and-STP/Create-and-lodge-a-pay-event/m-p/27536