Hey Leslye,
in order to create a menu link with a custom URL, please go to “Appearance -> Menus” in the admin panel, and click on “Custom links” in the accordion on the left; a form will open, where you can input the item title and the URL where it should link to. Then click on the “Add to menu” button and voila! :)
Sincerely,
Andrii / Satori Studio