I can't start off my personal statement - should I use a quote from someone famous that inspires me?

If you can't start your personal statement, then don't! By which I mean, focus on writing the main bulk of your personal statement, which should be relatively easier as you'll know what you want to mention, and then come back to your introduction later. I would advise against using a quote. Don't forget, it's a personal statement, where you're showcasing to a university why they should pick you. Because of this, you shouldn't use some of your 4000 character limit on someone else's words.