In general, people make pauses after period (。) or comma (、). However, for a long sentence, it is also alright to occasionally make a pause after a particle (助詞[じょし]) or after a te-form (～て). It is however not good to make a pause within a vocabulary term. === 良い一日をお過ごし下さい。／I wish you a good day.

Do you know about the small "tsu" often used in writing sentences? It marks a slight pause within a word, but not really during sentences. For example, if you were to write "datte" it would be written だって. Small "つ" marking the double "t", or a pause. da-te. (yep great explaining right here). I'm fairly sure the breaks you're talking about are people giving themselves a moment to think or consider what to say, like we do in English. People might also add "ano" or "eto" while they're thinking. So, from my experience at least, I find that in Japanese those breaks are fairly improvised, just taking a breath and thinking (if not thinking, just taking a breath). Hope this helped!! I know it isn't a great answer, that's why I'm posting as a comment instead. uwu