Adventures & experiences in contemporary technology
By default, a GNOME Terminal instance does not display a menu bar and that applies not only in GNOME Shell but also on the Cinnamon Desktop environment. In the latter, it is easy enough to display the menu bar using the context menu produced by right clicking in the window before going to Edit > Preferences and ticking the box for Show menubar by default in new terminals in the General section. After closing the Preferences dialogue, every new GNOME Terminal session will show the menu bar.
Unfortunately, it is not so easy in GNOME Shell though the context menu route does allow you to unhide the menu bar on a temporary basis. That is because the requisite tickbox is missing from the Preferences dialogue box displayed after navigating to Edit > Preferences in the menus. To address, you need the execute the following command in a terminal session:
gsettings set org.gnome.Terminal.Legacy.Settings headerbar false
This not only adds the menu bar on a permanent basis but it also adds the missing tickbox, populated as required. GNOME Shell may be minimalist in some ways but making this action harder looks like going a little too far.