Can someone tell me if my translation is correct? I have to write a short children's story. Here is what I have written so far:

Rufus habitaret in Romam.
Is es novem annos vetus.
ortus, gerebat bulla.
Bulla defenderet is de malum.

You've written...

Rufus lives in Rome.
"Is es" nine years aged. [I know you're trying to say, "He is nine years old," but what you've written is incorrect.]

I don't know what " ortus" is supposed to mean.

From there on...
... he was wearing an amulet.
The amulet [defends?] "is" from [malum]

If that last word is supposed to mean "evil" then it needs to be in the ablative case, not nominative or accusative.

What ARE you trying to say here? Give me all the English you are trying to translate, please.