Please! Advice, I have NO idea what step to take!

I'm currently completing my first year of university. The original plan was to obtain a bachelor degree, but I am missing on of the courses needed to apply right now, so I would beed another year of school before i can actually apply. But I've been talking to family friends and now I am considering getting my LPN, working for a few years, gainin experience and paying off my loan from this year, and then upgrading to an RN. And then maybe a BN later on. But I'm not sure which road to take. The LPN to RN to BN would enable me to gain a lot more experience and knowledge, and maybe even give me a better oppurtunity for work above just straight BN people, but I dont know what to do! Is there that large of difference between RN and BN? ANd i was also wondering how I would get into a certain area, such as oncology or transplant. PLEASE HELP AND OFFER ANY ADVICE POSSIBLE!!!!!!!!!!!!!!!!