Hello larrym,
You'll need to click on the hamburger icon at the top to see the left navigational menu. Let me show you where.
In your QuickBooks, click the three horizontal lines beside your account name. This process will let you hide and un-hide your left menu's.
Please see attached screenshot below.
You might also want to check this handy article for future reference: Help articles for QuickBooks Online.
If you have additional concerns, please don't hesitate to reach out to me anytime.