How to achieve full-screen display the content of the right side

Hi there, Ky!  I have some ideas on how you can achieve this effect.

You'll want to take a look in your Player properties.  There, you can modify how the menu appears.  You may want to move it to a topbar tab so that the user can open and collapse it as necessary.  It'll be out of the way, and your slide content will be front and center.

If you choose the Other function on the Player properties window, you can also control how your player and browser resize.  It might make sense to set your player to scale to fill the browser window.  Not all browsers will allow the browser window to resize, but you have that option in the settings, too.

If you didn't need any player features, you could look at creating a chromeless player.  It sounds like you'd want to preserve those functions when your learners need them, though, so let me know if those other choices work.