As it's already mentioned in wpForo FAQ, In Dashboard > Appearance > Menu admin page wpForo creates new navigation menu called "wpForo Navigation (wpForo Menu)" and attaches this menu to wpForo Menu location, it's the main, top forum menu. Here you can customize and translate all menus.
In case you want to say thank you !)
We'd really appreciate and be thankful if you leave a good review on plugin page. This is the best way to say thank you to this project and support team.