You need to open a new tab before you type the URL.

To do so, right-click just to the right of the existing tab.
In the drop-down menu, click New Tab.

After the new page opens, type the desired URL in the address bar.

Two other methods are:

ctrl + T opens a new tab

Also double-clicking on a blank spot on the tabbar.

HTH

Terry

also go to Tools, options , the tabs area, select items should open in new tab, apply

if you are clicking on a link in your current website and want that to open in a new tab right click the link and choose open in new tab.

Jean and Marooma,
So glad you know how to do what I need and are willing to share the info so readily. I've been using another browser that opens the tabs automatically and was afraid that Firefox wouldn't! I just tried the methods you both suggested and they work just fine. Hooray. Thank you. Kat

Ravencajun,
I hoped you'd still be here -- you helped me immeasurably in the past with your on-the-mark knowledge.

I'd already done the Tools > Option > Tabs > "New Pages Should Open in" > "A New Tab" and for some reason, that doesn't do the trick. I must have gotten the browser that was made on an off day. Ha

I've frequently made use of the right-click to open new tabs or go to links so I won't lose my place. That's getting easier to do at my age! :)

Thank you for responding. Kat