how to make everything open on external monitor

I m using MBP with a external screen. I want everything I open to open up in external monitor as I got really bad neck pain, so If I look down at laptop screen I can't do anything else due to pain.

ATM I can drag the window of application on external monitor but the contextual menu remains on laptop as well as dock.

How can I make sure that external screen is used or/and the laptop screen isn't used.

Apple has a support page which describes how to set the external monitor as your primary display.

Alternatively you can attach an external keyboard/mouse and just close your laptop.