First, don't let stories about the CPNE freak you out. There will always been negative stories out there, but this is YOUR exam, YOUR weekend, and YOU are in control of your own preparation.
Second, I wouldn't generally recommend starting to study for the CPNE until you are eligible and have applied already. CPNE study tends to be a very all-consuming process, and splitting it up or not being able to focus on it 100% is kind of counterproductive. But since you do have a bit of time to fill, it wouldn't hurt to start gathering your practice materials and/or looking at workshops. Workshops are best done when you've read the study guide and are familiar with the areas of care already, but workshops such as Sheri Taylor's (online and in-person, CPNE Workshop - CPNE - Excelsior CPNE
) have some resources you might be able to tap into sooner. Normally I would tell you to wait, but that is a good chunk of time to let it go to waste. But be aware that once you apply for the CPNE, it can take something like 4-6 months to actually go for your weekend.
The scariest thing about the CPNE is the "unknown" factor. You don't know much about the mechanics of it right now, but you'll have it all down cold by the time your weekend rolls around! Good luck.