"Head to" suggests to me that you are going to a specific place and you know where that place is. "I am headed to the store." "I am headed to Tokyo." "She was headed to school when she got a flat tire." When I think of "head for," I think of a more general place, and often more of a topographic place. "They say the river is going to flood because of all the rain, so we'd better head for higher ground." "The boat headed for land when the seas got rough." "Head for" is less commonly heard than "head to" in my opinion. If in doubt, I would use "head to" rather than "head for."

Good question. I would use ‘heading to’ in this case as you know exactly where you are going. ‘Heading for’ has more of an idea that you are going to a particular place but you might stop along the way or go in different directions to get there.