I've spent the last decade or so in the corporate world, so take this with a grain of salt.....
Really good managers listen to their staff and respect their staff's judgment. They are usually experts in MANAGING, thinking creatively and solving problems, not necessarily *doing* the job the staff does. Sure, it helps when you have a clue, but that's not necessarily the FOCUS of being a manager.
You've been at this facility a long time, you know how things work and you're also an RN....maybe the LPNs have more direct patient care experience, but that is their primary role, so they SHOULD be good at it. Keep being respectful to them and LISTENING and ACTING on their concerns and you'll earn their respect despite your limited experience as an RN.
Don't leave this job because you are feeling inexperienced next to the LPNs....leave it if its not want you want for your long-term career.