Look at the picture on this page
https://wiki.videolan.org/images/VLC_-_main.pngLook at the bottom of the screenshot where all the squares with the controls are. Hover your mouse over the different squares. The one with two arrows next to the last one on the right should say
"click to toggle between loop all, loop one, and no loop"
when you hover over it.
If you click that button it should toggle between repeating and not repeating.
You can also use the "L" key to toggle between repeating and not.
("L" is for Loop)