"I bought a lot of clothes at the department store."
Or, more accurately, "By going to the department store, I bought a lot of clothes." It's easier to think of the logical order and also know about particle placement:
(noun)を(action on noun)
(place/noun)で(action performed on/at noun/place)
In the section instance, ふく and たくさんかい work as the action (buying lots of clothes)
Or, more accurately, "My clothes were put in the many department stores I bought."
This is the closest readable translation into English.
Unlike other languages, rearrangement isn't easy with the basic level of learning Duolingo gives us. Usually, を goes near the end of the sentence.
This is a very detailed explanation, thanks for the post. I'm not sure I follow how
translates to "my clothes were put in the many department stores I bought" since the を particle indicates that the clothes were bought regardless of if the order is incorrect.
Perhaps you mean the above translates more like "I bought clothes in many department stores"?