How to make Lubuntu or LXDE panel to be on the top and behave like Ubuntu / MacOS panel (having the application menu placed to panel)
I have a small laptop screen and I like this ability of Ubuntu very much. I use LXDE with Lubuntu just because it takes far less system resources.
I'm not sure if I understand correctly what your system is but for a simple Lubuntu system (which comes with LXDE and other requisites), clicking anywhere in the blank area right at the top or the bottom of the screen should bring up this:
Then, in that window, clicking on "Panel Settings" should bring up this:
The options are self-explanatory here and the choices are quite a few.
As I said, this is with a proper Lubuntu installation.