4-time is the most familiar metre but it's only one of many possibilities. The first of the alternatives is 3-time / 3 beats in a bar / triple-metre.
For the time being we'll use the time signature 3/4. The top number tells you to count three in a bar, with a stress on 'one'. As before, the lower number indicates that a quarter-note / crotchet lasts for one beat (so a half-note still lasts for two etc.).
Here are all the possible combinations of quarter, half & dotted half-notes in bars of 3/4. Count and clap each one over and over until you get the feel of it. (Pick your own tempo, but you'll need to select a '3-Time' metronome).