You can probably get into a float pool at your hospital, but that isn't likely to expose you to the specialized areas like ICU, PACU, ED, maternity, etc. My recommendation is to shadow. I knew the first time I shadowed a nurse on a med-surg unit that it was not for me. I also knew the first time I shadowed in PACU that I was hooked, and to this day it is my favorite place in the whole hospital!
What do you like about the places you've worked? What did you dislike? Think about your preferences/strength in nurse-patient ratio, acuity/critical care needs, telemetry/technology (I LOVE monitors, but a lot of nurses hate them), continuity of care/LOS (i.e., do you have the same patient for an hour like me, or for a year like LTC), age of patients, type of health issue (if you don't like cardiac, don't work telemetry), amount of patient education, etc. Don't forget to look at your hours/days; urgent care usually requires every other weekend, but there is no call; OR/PACU require call but may not schedule nights depending on the facility, etc. Office nursing typically has no nights/weekends/holidays/call, but the pay may be lower, and you may miss the hospital.
Also, what do you want to learn? I'd like to learn wound care, but it doesn't come up in PACU and would require me to take a course or moonlight in the wound center!
I didn't take the self-test, and from people's responses I'm not sure you should, either! :) You have valuable experience coming from med-surg and LTC, and there is no reason you can't find a real niche in nursing! The sky really is the limit!