An administrator can set his/her menu view to everyone.
Check if this tool is available on your plan. You can find all the information about Bitrix24 plans on the pricing page.
First of all, you need to configure the main menu and add any custom items you need.
Read more in the article - Add items to the main menu.
Then you need to click Configure menu > Set my menu for everyone.
Specify users your menu will be set for (new users or all users) and click Save.
Users can configure their menus the way they need anyway, but the menu set by an administrator will be considered the default menu. If a user clicks Configure menu > Reset menu, the menu will be reset to the default view (set by an administrator).
