Go to Appearance > Customize >Menus.
From Menus, click “Add a Menu” button and you will be able to create a menu.
Now, click Add Items and you will be able to Add or Remove Menu Items according to your requirement.
Select the Menu locations.
Click Save and publish button.
You can also Set Menu from Backend
Step 1: Go to Backend>Dashboard>Appearances>Menu
Step 2: Click creates Menu, Give Menu Name and then click Create Menu. Then start adding pages to Menu then drag each item into the order you prefer. .
Step 3: Manage Location and Save Menu.