There should be a + button after the last tab on the tab bar, but it doesn't have a shape around it, so it seems to be just floating there and might be a little difficult to see. But can you find it there?

If it's not there, could you check the Customize dialog to see whether it somehow ended up in there and drag it back to its normal location? This article has the steps for that: Customize Firefox controls, buttons and toolbars.

Any luck?

Hi Mark, No, I don't seem to see any of what you're talking about. I see one tap for the page I'm currently on and there is no plus sign to be seen. I opened up the customize section and I see a plus sign up top, but it won't let me move it anywhere.

Okay, I moved it into that section and can now open up pages in tabs... from there. Can I not open it straight from the main page/screen anymore?

This is what I think is the default way it should appear (attached). If you don't mind clearing your toolbar customizations and re-customizing, you can use the "Restore Defaults" button in the Customize panel and see whether that brings it back.