Need help asking out a complete stranger

I [20M] met her [23F] on a course on university, which will consist of only 2 seminars. Yesterday was the first, she and three other psychology students is helping us with coaching students in lower years.

I've never seen her before and I doubt I will after the next seminar. I got really taken aback by her whole appearance, her style, her smile, her eyes yadayada. She's definetly a league above me but I dont't think it is impossible that she would find me attractive either.

Thing is, I've never really asked someone out. There have always been easier ways for me to getting to know someone, facebook isn't really an option, would feel really creept adding her when she probably doesn't even know my name. I don't really like to be this straight forward at once but here I don't think I have much of a choice. Obviously this is something that would be completely out of my comfort-zone but I am going to do it.

So am I just going to straight-up ask her to take a coffe sometime or are there easier ways to go about this?