。
She went to buy food.
Literal
She [topic-は] food [object-を] buying [to-に] went.
The purpose-of-motion construction [verb stem]+に+行く marks the goal of the trip: 買いに行く ('go to buy'). 食べ物 (たべもの, 'food') is the everyday word for edible things, and 行く is the plain motion verb 'to go' — neutral about leaving or arriving. The whole sentence reads as a simple, matter-of-fact errand.