Just like in everyday speeches, where you can speak the same thing differently to convey different subtle meanings, you can read in in many different ways. But to focus about pausing, there are a few rules of thumb I would like to suggest:
- pause at every end of sentence
- pause at every punctuation mark
- pause at the beginning of a clause
- pause it the same way you parse it
It is understandable that practicing reading aloud could be really frustrating at first. It is difficult enough to pronounce each word right, not to mention a sentence (or an entire passage). My advice is to make sure you understand what you read before you really read it aloud. Doing so requires you to parse the sentences correctly, and will help you know where to pause.
I tried recording myself reading it aloud. Here is how I paused:
Welcome to the VOA Learning English program. This is America. This week / Barbara Klein and Christopher Cruise tell about several American actors / who were widely recognized years ago. But they now are not big stars or famous like they once were. We ask them how they dealt with these changes.
I read it at my normal rate. It's 17.5 seconds long. Not particularly fast, but maybe a little too fast for beginners. Just remember to take it easy, and gradually build up your skill.