First of all, from a big perspective, you need to know the strength and weakness rules of time signatures. For example, the rules of each beat in 4/4 are: strong, weak, next strong, weak. The 3/4 beat is: strong, weak, weak. The second is the strong and weak symbols marked below the notes, such as: ff f mf sf p mp pp... and so on. As for the weak attack, for example, at the beginning of a phrase, it does not start from the whole measure, but from the next few beats of the measure. This is the weak attack rhythm. On the contrary, a phrase that starts with the first beat of the whole measure is a strong attack.

As for how strong it is and how weak it is, it depends on the style of the entire song. I hope this helps you~~~