The sentence with the incorrectly placed modifying phrase is:
Ana wants to buy new athletic shoes from her favorite store once she saves up enough money, Shoe Empire.
In this sentence, the phrase "from her favorite store" should be more clearly linked to "Shoe Empire" to avoid confusion. The placement of the modifying phrase causes ambiguity about which part of the sentence it is meant to modify. A clearer structure would be to say: "Ana wants to buy new athletic shoes from her favorite store, Shoe Empire, once she saves up enough money."