Ughhh... I would be very irritated. This friend sounds like she lacks boundaries, and it's going to be your burden to set some clear boundaries if the friendship is going to last.

Maybe you could ask for details about the places she wants to go with you, like where is this place, how far? I'd ask her to split the gas cost, and ask her if you guys need to stop to get cash.

21 calls in a row, omg... this sounds like a really needy friend, sorry if I'm mean but that can really zap your energy. I've attracted friends like this and end up really needing my space.