Epona, test taking is like anything else, nobody is born with the ability, and very few people have ever had training in how to take tests. I have always loved tests and so I have done well, going out of my way to do puzzles and tests all my life. Sure that gave me an edge, but my school has worked hard on making all exam questions into NCLEX-style questions, and their efforts make a whole lot more difference than all my previous test-taking experience. They spent lots of money on online NCLEX-style drills and NCLEX coaching courses. Now some of the students (like me) go all out on these, and some do the minimum. It's up to you.
Also you can buy prep books and online prep courses. It is worth spending money on these, because if you flunk, as you point out, it's all for nothing. You have to become determined to pass your first time, and there is no reason why you can't do it. The figures say your chances for success decline as the number of attempts increase, so set your mind on it and plan for it.
We study in a group, and our group has decided to study for school tests from an NCLEX prep book instead of our textbooks, and we prefer this even to lecture notes. This may cost us a couple of points in our school grades, but our heads are above water and more importantly this is our way of keeping our eye on the big prize, the NCLEX. The NCLEX score will be reported to our first employer, so doing well matters to all of us.