It's a bit like feeding fish - just give the animal as much as it will eat in 5-10 minutes, and it will self-regulate the amount that it eats. After several feedings, you will learn how much it needs. Four worms in one feeding sounds like a lot, but if the newt is OK and didn't throw any back up, I think it's fine.
At 6 inches, it is an adult, so it doesn't need to eat every day (unless its skinny). Every 2-4 days will be fine.
By the way, this forum expects native-English-speaking participants to use halfway decent English, including punctuation.