HOW TO PAUSE AND STOP BLENDER RENDER (Blender 2.83)

 The trick is just to untick overwrite in the output.

My problem was in naming the files. Better method is just to click the explorer buton and use it to go to your output directory. No need to type any name. Typing the name creates problems.

When you accept the folder, the name will end in \ indicating that it is just a directory.

Blender will just use numbers for the names of files. If you write a name, the numbers will be appended to the names that you write.

 The video editor is useful. When you add an image, it will give it 25 frames, i.e. 1 second of animation time. I changed it to 50 frames go get 2 seconds for the first image of my 50 frames of animation. I also add another image at the last frame.

In this way, the video pauses for 2 seconds at the first image, before animating for 2 seconds. At the end, it also pauses another 2 seconds.

This gives a more continuous experience than just 2 seconds of animation. Even Youtube starts disturbing the display of the video by overlaying a menu over the replay button.