Can you start a sentence with a preposition?
Yes, it’s quite common to start a sentence with a preposition, and there’s no reason not to do so.
For example, the sentence “To many, she was a hero” is perfectly grammatical. It could also be rephrased as “She was a hero to many,” but there’s no particular reason to do so. Both versions are fine.
Some people argue that you shouldn’t end a sentence with a preposition, but that “rule” can also be ignored, since it’s not supported by serious language authorities.