Just look at the music score. The beats will be written on the score.

If there is no music score, if you want to distinguish between four-four beats and four-two beats, you don’t rely on typing with your hands, but listening with your ears. If you want to use your hands to assist when listening, of course you can, but the real distinction depends on your ears. The difference between these two types of beats is that two beats are one unit or four beats are one unit. When listening, you can think about whether the music is composed of two beats as one unit or four beats as one unit. The former is two beats and the latter is four beats.

In practice, it is not easy to distinguish between these two types of beats. Some of the more typical ones can be heard at a glance, but some of the less typical ones are often ambiguous, so the actual ones are still based on what the composer wrote in the score. shall prevail.

As for the problem of distinguishing rhythms, the best way to learn is not to talk on paper, but to feel it by listening to a large number of examples. Which "this song" are you referring to? You can post the song so that everyone can help you sort out specific analysis methods.