How do I ask someone for a ride to a funeral?

The same way you would anywhere else. "Hey, I was wondering if you could drive me somewhere. There's a funeral I need to get to next Sunday at ten in the morning, I really have no other way to make it. Could you possibly drive me there?" You should tell them where the funeral is being held, when it starts (and when they should pick you up), and when it ends, assuming they won't be attending the funeral themselves. If they are also attending the funeral, then you can just ask if they could pick you up. Make it clear that you understand if they can't help you. Thank them if they agree to help.