First, shut down your Mac. Then calmly place of in the nearest waste receptacle. Next go buy a Windows system with better specs and touchscreen, and use the insanely intuitive, years old feature on that.
"...click and hold on the green fullscreen button in the upper-left corner of a window. The left half of your screen will become shaded in blue (if the left edge of the window is on the left side of your screen, which most of the time it is).
You can release your trackpad or mouse button to open the current window on the left half of your screen, or you can drag the window over to the right half of the screen, which will then become shaded in blue to open the app on the right half of the screen.